Chevrolet - Astro Van M - Workshop Manual - 1994 - 1994

Factory Workshop Manual Make Chevrolet Model Astro Van M Engine and year V6-262 4.3L VIN Z (1994) Please navigate through the PDF using the options provided by OnlyManuals.com on the sidebar. This manual was submitted by Anonymous Date 1st January 2018 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 12 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 13 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 14 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 20 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 21 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 22 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Control Module > Component Information > Locations > Door Lock Delay Module Power Door Lock Control Module: Locations Door Lock Delay Module Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Control Module > Component Information > Locations > Door Lock Delay Module > Page 28 Liftgate Wiring - RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear > Page 33 Power Door Lock Relay: Locations Door Lock Delay Relay Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear > Page 34 Power Door Lock Relay: Locations Door Lock Relay Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Diagrams > Door Lock Delay Relay C201A, Door Lock Delay Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Diagrams > Door Lock Delay Relay > Page 37 Power Door Lock Relay: Diagrams Door Lock Relay C241, Door Lock Relay C204A, Power Door Lock Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > ABS Main Relay > Component Information > Locations ABS Main Relay: Locations Fig. 223 EHCU/BPMV Replacement. The relay is located inside the Brake Pressure Modulator Valve (BPMV). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Brake Fluid Pump Relay > Component Information > Locations Brake Fluid Pump Relay: Locations Fig. 223 EHCU/BPMV Replacement. The relay is located inside the Brake Pressure Modulator Valve (BPMV). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations Electronic Brake Control Module: Locations Four-Wheel Antilock Brake Wiring, Engine Compartment Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 48 Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 49 C181, 4WAL EHCU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 50 Electronic Brake Control Module: Service and Repair Fig. 222 Intermediate Shaft & Universal Joint Assembly. Fig. 223 EHCU/BPMV Replacement. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove steering column intermediate shaft as follows: WARNING: Refer to Air Bags and Seat Belts / Air Bags (Supplemental Restraint Systems) / Service and Repair / Air Bag System Disarming & Arming. See: Body and Frame/Interior Moulding / Trim/Dash Board / Instrument Panel/Air Bag(s) Arming and Disarming a. Set wheels in straight ahead position. b. Mark upper universal joint yoke to steering shaft and lower yoke to steering gear wormshaft for installation reference. c. Remove upper and lower universal pinch bolts, Fig. 222. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 51 d. Remove steering gear frame bolts, then lower the steering gear. e. Remove intermediate shaft and universal joint assembly. 2. Disconnect brake lines from bottom of combination valve. 3. Disconnect electrical connector from combination valve. 4. Remove master cylinder and combination valve assembly. 5. Remove brake lines from EHCU/BPMV module, then disconnect module electrical connectors. 6. Remove EHCU/BPMV bracket attaching nuts and bolt, Fig. 223. 7. Remove module and bracket assembly from vehicle, then the module from bracket assembly. 8. Reverse procedure to install, noting the following: a.a Torque module to bracket bolts to 5 ft. lbs. b. Torque bracket attaching bolt to 33 ft. lbs., then the two attaching nuts to 20 ft. lbs. c. Torque brake line fittings to module to 16 ft. lbs. d. Torque brake line fittings to combination valve to 15 ft. lbs. e. Install lower yoke onto steering gear wormshaft aligning marks made during removal. f. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. g. Raise steering gear into position while guiding upper yoke assembly onto steering shaft, align marks made during removal. h. Torque steering gear to frame bolts to 55 ft. lbs. i. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. j. Measure Cardan joint operating angle as shown in Fig. 222. Angle must be 34-39°. k. Bleed brake system and EHCU/BPMV module. See: Brakes and Traction Control/Brake Bleeding Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: Customer Interest Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 61 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: All Technical Service Bulletins Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 67 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch Compressor Shaft Seal: All Technical Service Bulletins A/C - Insufficient Performance/Noisy Clutch File In Section: 1 - HVAC Bulletin No.: 63-12-16 Date: December, 1996 Subject: Insufficient A/C Performance and/or Noisy Compressor Clutch Assembly Models: 1994-95 Chevrolet Camaro 1994-95 Pontiac Firebird 1994-95 Chevrolet and GMC G/M/L Models Condition Some owners may comment on insufficient air conditioning performance and/or noisy compressor clutch assembly. Cause Premature wear of the compressor shaft seals. This wear will result in PAG oil leakage on the clutch drive and pulley, thus causing insufficient engagement of the compressor. Correction Install new shaft seal kit, P/N 2724954 and clutch driver, P/N 6580590. Procedure 1. Recover refrigerant. Refer to "Refrigerant Recovery" in Section 1B of the Service Manual. 2. Remove clutch driver plate and hub assembly as identified in Section 1D2 of the Service Manual. 3. Before removing the compressor shaft seals, the clutch pulley rotor face must be lightly sanded with 100 grit emery cloth to remove any burnt oil build up. Once the rotor face has been reconditioned, clean area thoroughly. If the clutch pulley rotor face is badly discolored and/or damaged, replace compressor assembly. 4. Remove compressor shaft seals as identified in Section 1D2 of the Service Manual. 5. Install the new shaft seal kit, P/N 2724954, and clutch driver, P/N 6580590, using the installation procedures in Section 1D2 of the Service Manual. This new seal kit will include oil wick pads and a shaft dust seal along with the typical compressor seals. Follow the detailed instructions included in the service kit to identify proper seal usage and sequence of installation. 6. Evacuate and re-charge the system as identified in Section 1B of the Service Manual. 7. Check system for leaks. Refer to "Leak Testing" in Section 1B of the Service Manual. Parts Information P/N Description Quantity 2724954 Shaft Seal Kit, 1 Compressor 6580590 Clutch Driver, 1 Compressor Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch > Page 73 Labor Operation Description Labor Time D4300 Seal, Seat and/or Use published O-Ring labor operation Compressor Shaft time - Replace Add Recondition Clutch 0.1 hr Surface Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart Compressor Shaft Seal: All Technical Service Bulletins A/C Compressor Seal Washer - Reference Chart File In Section: 1 - HVAC Bulletin No.: 63-12-15 Date: November, 1996 INFORMATION Subject: Reference Chart for A/C Compressor Seal Washers Models: 1997 and Prior Passenger Cars (Except Corvette and GEO) 1997 and Prior Light Duty Trucks (Except Tracker) GMSPO A/C compressors include a seal washer kit. These kits contain various color edge painted washer seals and inserts in which only two (2) washers and possibly one (1) insert are used. It has come to our attention that some packaging discrepancies were found and some of the seals cannot be properly identified for installation. These seals are very close in size and some of the seals were inadvertently edge painted the wrong color or not painted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 78 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 79 The chart shown will help to properly identify the seals. Use the chart by placing the seal over the pictured seal to identity inside and outside diameters and thickness. Because these seals are very similar in size, specifications are also listed in the chart. Important: If seals are damaged upon installation, obtain new seal kit. Seals will be available separately at a later date. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch > Page 85 Labor Operation Description Labor Time D4300 Seal, Seat and/or Use published O-Ring labor operation Compressor Shaft time - Replace Add Recondition Clutch 0.1 hr Surface Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 90 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 91 The chart shown will help to properly identify the seals. Use the chart by placing the seal over the pictured seal to identity inside and outside diameters and thickness. Because these seals are very similar in size, specifications are also listed in the chart. Important: If seals are damaged upon installation, obtain new seal kit. Seals will be available separately at a later date. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 92 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 93 C253, Cruise Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 94 Cruise Control Module: Description and Operation The module monitors cruise control switch position, signals from the speed sensor, servo position and release switch operation, then operates vacuum valves within the servo unit to control servo operation and vehicle speed. The module also contains a speed limiting function which prevents system operation at speeds below approximately 25 mph. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations Blower Motor Relay: Locations Image updated by TSB 461103 Dated December 1994 Located on multi use bracket, at RH side of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations > Page 99 C164, HI A/C Blower Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions Audible Warning Device Control Module: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 105 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 106 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 107 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 108 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 109 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 110 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 111 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 112 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 113 Audible Warning Device Control Module: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 114 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 115 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 116 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 117 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 118 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 119 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 120 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 121 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 122 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 123 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 124 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 125 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 126 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 127 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 128 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 129 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 130 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 131 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 132 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 133 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 134 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 135 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 136 Audio Alarm Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Control Unit > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Control Unit > Component Information > Locations > Page 141 C260, DRL Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Relay > Component Information > Locations Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Relay > Component Information > Locations > Page 145 C144, DRL Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location Exterior Lighting Module: Technical Service Bulletins Exterior Lights - Revised Schematic, Component Location File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-81-07 Date: September, 1996 SERVICE MANUAL UPDATE Subject: Section 8A-110 - Exterior Lights - Revised Text Pages and Art Pages Models: 1994 Chevrolet and GMC M/L Models Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 150 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 151 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 152 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 153 This bulletin revises the System Schematic, Component Location Index, Connector End View and Component Location View for the Exterior Lights System in Section 8A-110. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Fog/Driving Lamp Relay > Component Information > Locations Fog/Driving Lamp Relay: Locations Instrument Panel Fog Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Fog/Driving Lamp Relay > Component Information > Locations > Page 157 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Horn Relay > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Specifications Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center Relay Box: Locations Convenience Center Fuse Block And Convenience Center Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 167 Crossbody Harness The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 168 Relay Box: Locations Relay Center The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap C283, Convenience Center Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 171 C206, Convenience Center To I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 172 C206, Convenience Center To I/P Cluster In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 173 C206, I/P Cluster To Convenience Center In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 174 C206, I/P To Convenience Center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Page 175 Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 182 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 183 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 184 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 185 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 186 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 187 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 188 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 189 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 190 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 191 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 192 Powertrain Control Module Mounting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description Engine Control Module: Diagrams Connector Description PCM Connector Terminal End View (1 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 195 PCM Connector Terminal End View (2 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 196 PCM Connector Terminal End View (3 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 197 PCM Connector Terminal End View (4 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 198 Engine Control Module: Diagrams C204 (32-Pin Blue) C204, Powertrain Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 199 C204, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 200 Engine Control Module: Diagrams C288 (32-Pin Red) C288, Powertrain Control Module C288, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 201 Engine Control Module: Description and Operation OPERATION: The control module is located in the passenger compartment and is the control center of the Computer Command Control system. The control module constantly receives information from various sensors. The computer performs the diagnostic functions of the system. The computer can recognize operational problems and alert the driver through the Malfunction Indicator Lamp (MIL) (Service Engine Soon light). The computer stores a trouble code which identifies the problem area to diagnose and repair. The computer is designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The computer has a learning ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected to clear trouble codes or for repair, the learning process has to begin all over again, and a change may be noticed in the driving performance of the vehicle. To reset the vehicles learning ability, make sure the engine is at operating temperature and operate the vehicle at part throttle, moderate acceleration, and idle conditions, until normal performance returns. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 202 Engine Control Module: Service and Repair Control Module Mounting CAUTION: [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, DO NOT touch the connector pins or soldered components on the circuit boards. NOTE: When replacing a production control module with a service controller, transfer the broadcast DTC and production control module part number to the controller label. DO NOT record information on the access cover. REMOVAL: 1. Disconnect the negative battery terminal. 2. Remove passenger kick panel. 3. Disconnect control module harness connectors. 4. Remove control module retainer and control module. 5. Remove brackets and modules if equipped.. 6. Remove access cover and PROM (MEM-CAL). INSTALLATION: 1. Install PROM (MEM-CAL) and access cover on to new control module. 2. Install mounting brackets and module(s) if equipped. 3. Connect control module harness connectors. 4. Install control module and retainer. 5. Install passenger kick panel. 6. Connect the negative battery terminal. 7. Perform functional check. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Control Unit > Component Information > Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 218 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 219 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 220 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 226 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 227 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 228 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 229 Fuel Pump Relay: Locations FUEL PUMP RELAY Engine Compartment Wiring, LH Side The Fuel Pump Relay is located in the RH front of cowl, above blower motor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 230 C214, Fuel Pump Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 231 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 232 Fuel Pump Relay: Service and Repair Mounted To Right Side Engine Compartment REMOVAL 1. Verify that ignition switch is in the "OFF" position. 2. Disconnect wiring harness plug. 3. Remove fuel pump relay. INSTALLATION 1. Install new fuel pump relay. 2. Reconnect wiring harness plug to relay. 3. Verify correct operation to confirm repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Variable Induction Control Relay > Component Information > Locations Engine Wiring - RH Cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Diagrams C103, Ignition Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Diagrams > Page 243 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: NOTE: It is not necessary to remove ignition distributor assembly from engine. 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. Tighten to 2 Nm (18 lb. in.) 4. Install pick up coil. 5. Install cap and rotor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > System Component Locations Fig. 2 Air Bag System Component Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > System Component Locations > Page 249 Diagnostic Energy Reserve Module Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > Page 250 C423, Resistor Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > Page 251 Air Bag Control Module: Description and Operation A function of the DERM is to supply the deployment loop with a 36 volt loop reserve to ensure sufficient energy to deploy the air bag if the ignition feed to the arming sensor is lost during a frontal collision. Another function of the DERM is electrical system diagnostics. The DERM can detect circuit and component malfunctions within the deployment loop. Voltage drops across components within the loop are measured during non-deployment conditions. If the monitored voltages fall outside of the expected limits, the DERM will indicate a malfunction through the storage of a diagnostic trouble code and the illumination of the air bag warning light. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Service and Repair > Diagnostic Energy Reserve Module (DERM) Air Bag Control Module: Service and Repair Diagnostic Energy Reserve Module (DERM) Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. Do not open DERM case for any reason. Touching connector pins or soldered components may cause electrostatic discharge damage. Repair of a malfunctioning DERM is by replacement only. 1. Remove DERM mounting bracket. 2. Remove connector position assurance lock, then disconnect DERM electrical connector. 3. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Service and Repair > Diagnostic Energy Reserve Module (DERM) > Page 254 Air Bag Control Module: Service and Repair Sensing and Diagnostic Module Replacement (SDM) Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Disconnect battery ground cable. 2. Remove left front seat. 3. Remove carpet retaining sill trim molding. 4. Fold back carpet to access SDM. 5. Disconnect connector assurance and electrical connector. 6. Remove SDM attaching nuts and SDM module. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations Shift Interlock Relay: Locations Behind LH side of I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations > Page 260 Shift Interlock Relay: Diagrams C217A, Brake/Transmission Shift Interlock Relay C218A, Brake/Transmission Shift Interlock Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Windows and Glass > Heated Glass Element Relay > Component Information > Locations Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Windows and Glass > Heated Glass Element Relay > Component Information > Locations > Page 265 Heated Glass Element Relay: Diagrams C235, Rear Window Defogger Relay C235, Defogger Timer Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Component Locations Power Door Lock Switch: Component Locations Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Component Locations > Page 272 RH Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Component Locations > Page 273 Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Page 274 Power Door Lock Switch: Diagrams C604, Front RH Power Door Lock Switch C504, Front Door Lock Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Locations > Component Locations Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Locations > Component Locations > Page 279 Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch C248, Crossbody To Mirror Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch > Page 282 C275, Power Mirror Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch > Page 283 C248, Mirror Switch To Crossbody Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Locations Power Seat And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Locations > Page 287 C321, Driver's Seat Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Locations > Compartment Lid Release Switch, Rear Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Locations > Compartment Lid Release Switch, Rear > Page 292 Trunk / Liftgate Switch: Locations Liftgate Strut Switch Upper RH rear D-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear C203, Liftgate Release Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear > Page 295 C918, Liftgate Key Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear > Page 296 Trunk / Liftgate Switch: Diagrams Liftgate Strut Switch C417, Liftgate Strut Switch C417, Liftgate Strut Switch (Body Side) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Brake Fluid Pressure Sensor/Switch > Component Information > Locations Brake Fluid Pressure Sensor/Switch: Locations Four-Wheel Antilock Brake Wiring, Engine Compartment On brake master cylinder Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Brake Fluid Pressure Sensor/Switch > Component Information > Locations > Page 301 C146, Brake Pressure Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations Fuse Block And Rear Body Harness Fuse Block And Rear Body Harness Below LH side of I/P, on park brake lower assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch C255, Park Brake Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch > Page 307 Parking Brake Warning Switch: Diagrams Park Brake Warning Switch In-Line C225, Park Brake Warning Switch In-line C225, Park Brake Warning Switch In-line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Locations > LH Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Locations > LH > Page 312 Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Diagrams > RH Wheel Speed Sensor: Diagrams RH C189, RH Front Wheel Sensor C189, RH Front Wheel Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Diagrams > RH > Page 315 Wheel Speed Sensor: Diagrams LH C190, LH Front Wheel Sensor C190, LH Front Wheel Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Service and Repair > Front Wheel Speed Sensor Wheel Speed Sensor: Service and Repair Front Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. Remove hub and rotor assembly. 4. Disconnect wheel sensor electrical connector. 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Service and Repair > Front Wheel Speed Sensor > Page 318 Wheel Speed Sensor: Service and Repair Rear Wheel Speed Sensor Fig. 58 Rear Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Remove brake drum. 3. Remove primary brake shoe. 4. Disconnect sensor electrical connector. 5. Remove sensor wire from rear axle clip. 6. Remove speed sensor attaching bolts, Fig. 58, then remove sensor by pulling wire through hole in backing plate. 7. Reverse procedure to install. Torque speed sensor attaching bolts to 26 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 326 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 329 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 330 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 331 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 332 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 333 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 334 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 335 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 336 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 337 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 338 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 339 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 340 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 341 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 342 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 343 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 344 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 345 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 346 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 347 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 348 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 349 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 350 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 351 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 352 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 353 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 354 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 355 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 356 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 357 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 358 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 359 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 360 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 361 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 362 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor Temperature Sensor (Gauge): Locations Engine Coolant Temperature (ECT) Gage Sensor Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 367 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 368 Engine Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 373 C251, Cruise Control Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 374 Brake Switch (Cruise Control): Description and Operation The brake switch is used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 375 Brake Switch (Cruise Control): Adjustments With the brake pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams C254, Cruise Control Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Page 379 Clutch Switch: Description and Operation The clutch switch is used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Page 380 Clutch Switch: Adjustments With the clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Description and Operation Cruise Control Switch: Description and Operation Fig. 1 Cruise Control Switch The cruise control switch, Fig. 1, consists of a 3 position slide-type switch and a set/coast switch button. To operate the system, the slide switch must be in on position and vehicle speed must be above 25 mph. The system is engaged at the desired speed by fully depressing, then releasing the set/coast button. Cruise speed can be increased from set position by accelerating vehicle to desired speed, then pressing and releasing button. In order to decrease speed, the set/coast button is held in the fully depressed position (disengaging system), then released when the desired speed is reached. The system can be disengaged at any time by depressing the brake or clutch pedal, or by moving the slide switch to off position. If the system is disengaged by depressing the brake or clutch pedal, the last set speed will be retained in the module memory until the slide switch or ignition switch is moved to off position. Momentarily moving the slide switch to the resume/accel position will cause the vehicle to accelerate to the last set speed and maintain that speed. If the slide switch is held in the resume/accel position, the vehicle will continue to accelerate until the switch is released. When the switch is released, the speed that the vehicle accelerated to becomes the new set speed. The slide switch also allows a tap-up function to increase cruise set speed in 1 mph increments. With the cruise control engaged and operating, tapping-up is done by pressing the slide switch to the resume position, then quickly releasing it. This procedure can be repeated 10 times before the system must be reset to a new speed in the conventional manner. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Description and Operation > Page 384 Cruise Control Switch: Service and Repair 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect cruise control connector from main harness connector and attach a suitable length of flexible wire to cruise control harness. Fig. 10 Cruise Control Switch replacement 3. Tape joint between main and control harness to aid removal, then remove control assembly, Fig. 10. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 403 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 404 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 405 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 406 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Locations Blower Motor Switch: Locations Air Conditioning, Heater Control I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Locations > Page 411 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Locations > Page 412 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch C261, Auxiliary A/C Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 415 C243, Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 416 C243, Heater Blower Control Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 417 C243, Heater Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Evaporator Control Switch Refrigerant Pressure Sensor / Switch: Locations Evaporator Control Switch On multi use bracket, at RH side of cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Evaporator Control Switch > Page 422 Refrigerant Pressure Sensor / Switch: Locations High Pressure Cutout Switch Back of A/C compressor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Page 423 C166, Pressure Cycling Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 429 Dimmer Switch: Locations Instrument Panel, LH Side Headlights Switch Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 430 Dimmer Switch: Diagrams C299, Resistance Wire To Panel Dimmer Switch C299, Panel Dimmer Switch To Resistance Wire C218, Panel Dimmer Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 435 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 436 RH I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 437 Door Switch: Locations Door Jamb Switch, Sliding Side Side Door Switches And Wiring In RH B-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Page 438 C325, LH Door Jamb Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations Fuel Pump And Sender Assembly (Typical) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations > Page 442 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull fuel pump up into attaching hose while pulling outward from the bottom support. ^ Do not damage rubber insulator or strainer. INSPECTION: 1. Inspect fuel pump attaching hose for signs of deterioration. 2. Inspect rubber sound insulation at bottom of pump for deterioration. INSTALLATION: 1. Install pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). 3. Install cam lock assembly. Turn cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect negative battery cable. 6. START vehicle and check for fuel leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations Fuse Block And Rear Body Harness Fuse Block And Rear Body Harness Below LH side of I/P, on park brake lower assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch C255, Park Brake Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch > Page 448 Parking Brake Warning Switch: Diagrams Park Brake Warning Switch In-Line C225, Park Brake Warning Switch In-line C225, Park Brake Warning Switch In-line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Backup Lamp Switch > Component Information > Locations Backup Lamp Switch: Locations Instrument Panel, LH Side On steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Backup Lamp Switch > Component Information > Locations > Page 453 C217, Backup Lamp Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions Brake Light Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 459 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 460 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 461 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 462 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 463 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 464 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 465 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 466 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 467 Brake Light Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 468 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 469 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 470 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 471 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 472 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 473 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 474 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 475 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 476 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 477 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 478 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 479 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 480 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 481 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 482 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 483 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 484 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 485 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 486 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 487 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 488 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 489 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 490 Brake Light Switch: Connector Views C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 491 Brake Light Switch: Electrical Diagrams PCM Wiring Diagram (3 Of 5) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 492 Exterior Lamps (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 493 Exterior Lamps (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 494 Exterior Lamps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 495 Brake/Transmission Shift Interlock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 496 Cruise Control Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Page 497 Brake Light Switch: Service and Repair Fig. 15 Stop Lamp Switch Replacement. The zero adjust stop lamp switch does not need adjustment because the switch is installed along with the brake push rod and held by a single retainer. 1. Disconnect battery ground cable. 2. Disconnect stop lamp switch electrical connector. 3. Disconnect retainer from brake pedal pin, Fig. 15. 4. Remove stop lamp switch by unsnapping from pushrod. 5. To install switch, snap into pushrod. 6. Snap retainer onto brake pedal pin, then connect switch electrical connector. 7. Connect battery ground cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 502 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 503 RH I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 504 Door Switch: Locations Door Jamb Switch, Sliding Side Side Door Switches And Wiring In RH B-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Page 505 C325, LH Door Jamb Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Fog/Driving Lamp Switch > Component Information > Locations Fog/Driving Lamp Switch: Locations Instrument Panel Fog Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Fog/Driving Lamp Switch > Component Information > Locations > Page 509 Radio, Clock And Memory Feed Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations Headlamp Dimmer Switch: Locations Instrument Panel, LH Side On LH side of steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 513 Headlamp Dimmer Switch: Service and Repair Fig. 19 Ignition Lock & Dimmer Switch Replacement. 1. Disconnect battery ground cable. 2. Remove lower steering column cover. 3. Remove washer head screw (54) and hexagon washer head tapping screw (69), Fig. 19. 4. Remove dimmer switch assembly, Fig. 19. 5. Remove flat head screw (67), then the ignition switch assembly with switch actuator rod, Fig. 19. 6. Remove switch actuating rod from ignition switch. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations Headlamp Switch: Locations Headlights Switch Wiring Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations > Page 517 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions Headlamp Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 520 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 521 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 522 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 523 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 524 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 525 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 526 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 527 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 528 Headlamp Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 529 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 530 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 531 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 532 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 533 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 534 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 535 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 536 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 537 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 538 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 539 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 540 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 541 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 542 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 543 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 544 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 545 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 546 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 547 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 548 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 549 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 550 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 551 C202, Headlight Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 552 Headlamp Switch: Electrical Diagrams Light Switch Details (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 553 Light Switch Details (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Page 554 Headlamp Switch: Description and Operation HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Headlamp circuit draws too much current. When the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off and resets automatically. When the Light Switch is in HEAD, the Headlamp Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beam Indicator also receives voltage along with the High Beams. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Page 555 Headlamp Switch: Testing and Inspection HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Headlamp circuit draws too much current. When the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off and resets automatically. When the Light Switch is in HEAD, the Headlamp Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beam Indicator also receives voltage along with the High Beams. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Horn Switch > Component Information > Locations Horn Switch: Locations In steering wheel Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams Turn Signal Switch: Diagrams C207, Multi-Function Switch In-Line C207, Turn Signal Switch C207, Turn Signal Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 562 C207, Turn Signal Switch C207, Turn Signal Switch In-Line C207, Turn Signal Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 563 C207, Turn Signal Switch In-Line C207, Multi-Function Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 564 Turn Signal Switch: Service and Repair Fig. 8 Lock Bolt Guard Removal. Fig. 17 Turn Signal Switch Replacement. 1. Place ignition switch in Lock position to prevent coil assembly from moving off center. 2. Disconnect battery ground cable. 3. Remove steering wheel. WARNING: Refer to Air Bags and Seat Belts/ Air Bags (Supplemental Restraint Systems)/ Service and Repair/ Air Bag System Disarming & Arming. 4. Remove coil assembly retaining ring from upper steering column. 5. Remove SIR coil assembly. Let coil assembly hang freely. 6. Remove wave washer. 7. On models with tilt steering column, remove lock bolt guard assembly, Fig. 8, as follows: a. Place ignition switch in Run position. b. Rotate steering shaft assembly until block tooth is at seven o'clock position and bolt guard screws are accessible through wide slots in shaft lock. c. Loosen screws on lock bolt guard until guard can be removed. d. Place ignition switch to Lock position. 8. Remove shaft lock retaining ring using tool No. J-23653-SIR, or equivalent, to push down shaft lock. Discard ring. 9. Remove shaft lock, Fig. 8. 10. Remove turn signal canceling cam assembly. 11. Remove upper bearing spring. 12. Remove upper bearing inner race and inner race seat. 13. Position turn signal to right turn position. 14. Remove multi-function lever and hazard knob assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 565 15. Remove turn signal switch arm. 16. Remove turn signal switch as follows: a. Remove turn signal switch screws. b. Disconnect switch electrical connectors. c. Remove wiring protector, Fig. 17. d. Gently pull wiring harness through column to remove turn signal switch, Fig. 17. 17. Reverse procedure to install. Torque turn signal switch arm screw to 20.0 inch lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 573 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 576 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 577 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 578 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 579 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 580 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 581 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 582 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 583 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 584 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 585 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 586 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 587 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 588 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 589 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 590 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 591 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 592 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 593 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 594 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 595 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 596 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 597 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 598 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 599 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 600 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 601 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 602 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 603 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 604 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 605 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 606 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 607 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 608 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 609 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 617 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 620 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 621 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 622 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 623 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 624 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View Manifold Pressure/Vacuum Sensor: Locations Assembly View MAP Sensor (Typical) The Manifold Absolute Pressure (MAP) Sensor is located on a bracket, mounted to the intake manifold on the passenger side next to the throttle body assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View > Page 630 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 633 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 634 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 635 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 636 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 637 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 638 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 639 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 640 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 641 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 642 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 643 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 644 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 645 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 646 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 647 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 648 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 649 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 650 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 651 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 652 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 653 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 654 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 655 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 656 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 657 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 658 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 659 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 660 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 661 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 662 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 663 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 664 C104, MAP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 665 DTC 33 Circuit Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 666 Manifold Pressure/Vacuum Sensor: Description and Operation Manifold Absolute Pressure (MAP) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. The computer sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the computer can determine the manifold absolute pressure. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum, which requires less fuel. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the computer to automatically adjust for different altitudes. The computer uses the MAP sensor to control fuel delivery and ignition timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 675 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 681 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 695 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 705 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Page 706 Oxygen Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View Oxygen Sensor Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View > Page 709 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 712 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 713 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 714 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 715 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 716 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 717 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 718 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 719 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 720 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 721 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 722 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 723 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 724 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 725 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 726 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 727 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 728 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 729 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 730 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 731 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 732 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 733 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 734 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 735 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 736 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 737 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 738 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 739 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 740 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 741 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 742 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 743 C108, Oxygen Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 744 Heated Oxygen Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 745 Oxygen Sensor: Description and Operation FUNCTION: The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION: The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315~C (600~F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Due to the electrolytic properties of the element the oxygen concentration differences between the reference air and the exhaust gases produce small voltages. OPERATION: A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES: An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE: The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/DIAGNOSTIC CHARTS/CODE 13. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 746 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION: ^ Connectors and wires ^ Housing and insulator for cracks/damage ^ Sensor tip for silicone contamination (white powdery coating) PERFORMANCE TEST: Checks working range and response (speed). 1. Warm engine 2. Install DVOM between sensor and ground (2 volt D.C. range) 3. "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). 4. Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. 5. Drive system lean: Create a vacuum leak from a source that is not an ECM input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE: After each test the O2 sensor should return to normal operating range within two to three seconds. 6. O2 Sensor should be replaced for failure to pass any of the tests above. NOTE: A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. 7. Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 747 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 753 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 756 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 757 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 758 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 759 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 760 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 761 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 762 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 763 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 764 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 765 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 766 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 767 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 768 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 769 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 770 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 771 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 772 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 773 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 774 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 775 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 776 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 777 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 778 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 779 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 780 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 781 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 782 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 783 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 784 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 785 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 786 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 787 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 788 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 789 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 790 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 791 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 796 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 797 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 798 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 799 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor (VSS) Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 806 Transfer Case Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 807 Vehicle Speed Sensor: Diagrams C240, I/P To VSS In-Line C212, VSS To I/P In-Line C394, Vehicle Speed Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation Vehicle Speed Sensor: Description and Operation Circuit Operation The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation > Page 810 Vehicle Speed Sensor: Description and Operation Component Description Vehicle Speed Sensor (VSS) PURPOSE: The Vehicle Speed Sensor (VSS) provides information to the ECM for control of transmission Torque Converter Clutch (TCC), speedometer, odometer and cruise control. OPERATION: The VSS is a Permanent Magnet (PM) generator that produces a pulsing A/C voltage whenever vehicle speed exceeds about 3 mph (5 Kph). The A/C voltage level and the number of pulses increases with vehicle speed and is converted by the ECM to MPH (Kph). A VSS buffer is incorporated into the ECM for operating the instrument panel speedometer and odometer. LOCATION: Transaxle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Vehicle Speed Sensor: Initial Inspection and Diagnostic Overview Check condition of BRAKE Fuse. If fuse is blown, locate and repair source of overload. Replace fuse. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 813 Vehicle Speed Sensor: Symptom Related Diagnostic Procedures Cruise Control Does Not Operate Properly (Part 1 Of 2) Cruise Control Does Not Operate Properly (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 814 Speedometer And Odometers Do Not Operate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 815 Vehicle Speed Sensor: Component Tests and General Diagnostics The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 821 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 822 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 823 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 824 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 830 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 833 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 834 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 835 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 836 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 837 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 838 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 839 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 840 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 841 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 842 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 843 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 844 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 845 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 846 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 847 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 848 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 849 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 850 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 851 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 852 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 853 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 854 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 855 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 856 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 857 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 858 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 859 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 860 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 861 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 862 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 863 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 864 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 865 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 866 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 867 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 868 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision > Page 874 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 877 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 878 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 879 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 880 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 881 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module Arming Sensor Module Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module > Page 887 Discriminating Sensors Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module > Page 888 Discriminating Sensors Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Page 889 C225A, Sensor Arming Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor Impact Sensor: Description and Operation Arming Sensor The arming sensor is a protective switch located in the power side of the deployment loop. It is calibrated to close at low level speed changes. This ensures that the inflator module is connected directly to the 36 Volt Loop Reserve (VLR) output of the DERM when either of the discriminating sensors close. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor > Page 892 Impact Sensor: Description and Operation Discriminating Sensors There are two discriminating sensors in the air bag system. They are wired in parallel on the low (ground) side of the deployment loop. These sensors are calibrated to close with speed changes severe enough to warrant deployment. A diagnostic resistor is connected in parallel with the switch contacts within each of the discriminating sensors. These parallel resistors supply the ground path for the current passing through the deployment loop during normal operation. This current flow results in voltage drops across each component in the deployment loop. The DERM monitors these voltage drops to detect malfunctions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor Impact Sensor: Service and Repair Arming Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Raise and support vehicle. 2. Disconnect sensor electrical connector from retainer, remove Connector Position Assurance (CPA) lock from connector, then disconnect connector. 3. Remove sensor mounting bolts and sensor from vehicle. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor > Page 895 Impact Sensor: Service and Repair Forward Discriminating Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Remove windshield washer reservoir. 2. Remove discriminating sensor electrical connector from retainer, then the Connector Position Assurance (CPA) lock from connector. 3. Disconnect sensor electrical connector. 4. Raise and support vehicle, then remove sensor harness from retainers. 5. Remove sensor bolts, then the sensors. 6. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Occupant Sensor > Component Information > Technical Service Bulletins > Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Sensor/Switch > Component Information > Locations Seat Sensor/Switch: Locations In LH safety belt retractor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 908 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 909 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 910 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 911 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 912 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 913 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 914 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 915 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 916 Neutral Safety Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 917 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 918 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 919 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 920 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 921 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 922 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 923 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 924 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 925 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 926 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 927 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 928 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 929 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 930 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 931 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 932 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 933 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 934 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 935 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 936 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 937 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 938 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Page 939 Neutral Safety Switch: Service and Repair Fig. 13 Neutral Safety & Back-up Lamp Switch Replacement REMOVAL 1. Disconnect battery ground cable. 2. Disconnect switch electrical connector from switch terminals, Fig. 13. 3. Remove switch from steering column jacket. INSTALLATION 1. Place gear selector in Neutral position. 2. Align actuator on switch with hole in the shift tube, Fig. 13. 3. Position rearward side of switch (connector side) to fit into cutout in the lower shift bowl. 4. Push down on front of switch. Tangs on housing back will snap into place in rectangular holes in the shift bowl. 5. Connect switch electrical connector, then the battery ground cable. 6. Adjust switch by moving the gear selector to Park position. The main housing and housing back should ratchet, providing proper switch adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 945 Brake Switch - TCC: Diagrams C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 949 Fluid Pressure Sensor/Switch: Locations The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 950 Fluid Pressure Sensor/Switch: Description and Operation Pressure Switch Manifold NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Pressure Switch Manifold (PSM) is a gear range sensing device used by the control module to sense what gear has been selected by the vehicle operator. The PSM is located on the valve body and consists of five pressure switches combined into one unit. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 955 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 956 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 957 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 958 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch Heated Glass Element Switch: Locations Rear Defogger Switch Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch > Page 967 Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch > Page 968 Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations Door Wiring W/Power Door Locks, Power Windows And Power Mirrors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations > Page 972 Power Window Switch: Diagrams C500, Front LH Power Window Switch C600, Front RH Power Window Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Locations Multi-Function Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch C415, Wiper Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 979 Wiper Switch: Diagrams Multi-Function Switch In-Line C207, Multi-Function Switch In-Line C207, Multi-Function Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 980 C415, Motor To Wiper Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 981 Wiper Switch: Service and Repair Remove or Disconnect NOTICE: Place ignition to "LOCK" position to prevent uncentering coil assembly (3). 1. Disable the SIR system. 2. Negative (-) battery cable. 3. Coil assembly retaining ring (2). 4. Inflatable restraint coil assembly (3). a). Let switch hang freely if removal is not needed. b). To remove coil assembly (3), do steps 5 through 17. 5. Wave washer (4). 6. Shaft lock spacer (7). 7. Shaft lock retaining ring (8) using 3 23653-SIR to push down shaft lock (9). Dispose of ring (8). 8. Shaft lock (9) from steering shaft assembly (46). 9. Turn signal cancel cam assembly (10). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 982 10. Upper bearing spring (11). 11. Thrust washer (17). 12. Turn signal to "RIGHT TURN" position (up). 13. Multi-function lever and hazard knob assembly. 14. Washer head screw (13) and switch actuator arm (14). 15. Three cross recess screws (12). 16. Turn signal switch assembly (15). Let switch hang freely, if removal is not needed. To remove, turn signal switch (15). a). Turn signal switch connector from vehicle wire harness and connector body bracket assembly (56). b). Hexagon nut (57). c). Connector body bracket (56). d). Wiring protector (43). e). Turn signal switch (15) connector through column. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 983 NOTICE: Coil assembly (3) will become uncentered if: 1). Steering column is separated from steering gear and is allowed to rotate, or 2). Centering spring is pushed down, letting hub rotate while coil (3) is removed from steering column. 17. Inflatable restraint coil assembly (3) with wire harness from column assembly. a). Wiring protector (43). b). Ensure that connector shroud (5) has been removed. Attach a length of mechanics wire to terminal connector to aid in reassembly. c). Gently pull wire through column. NOTICE: When removing buzzer switch assembly (18) buzzer switch retaining clip (42) may become disconnected. Ensure that retaining clip (42) does not drop into column assembly. Failure to do so may result in component damage or malfunctioning of steering column. 18. Buzzer switch assembly (18) with buzzer switch retaining clip (42). Clip (42) from buzzer switch (18). 19. Lock retaining screw (19). 20. Steering column lock cylinder set (22). Install or Connect NOTICE: Ensure all fasteners are securely seated before applying needed torque. Failure to do so may result in component damage or malfunctioning of steering column. 1. Steering column lock cylinder set (22). 2. Lock retaining screw (19). Tighten screw (19) to 4.5 N-m (40 lb.in.) 3. Buzzer switch retaining clip (42) to buzzer switch (18). Buzzer switch (18) with retaining clip (42) to steering column housing assembly (20). Ensure that clip (42) does not drop into column assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 984 4. Coil assembly (3) wire harness through column. Let coil hang freely. 5. Turn signal switch assembly (15) wire harness through steering column. a). Wire protector (43). b). Connector body bracket (56) with hexagon nut (57). Tighten nut (57) to 4.0 N-m (35 lb.in.). c). Turn signal switch (15) connector to vehicle wire harness and connector body bracket (56). 6. Turn signal switch assembly (15) with screws (12). Tighten screws (12) to 3.4 N-m (30 lb.in.). 7. Switch actuator arm (14) and screw (13). Tighten screw (13) to 2.3 N-m (20 lb.in.). 8. Hazard knob assembly and multi-function lever. 9. Thrust washer (17). 10. Upper bearing spring (11). 11. Turn signal cancel cam assembly (10). Lubricate with grease, synthetic (service kit). 12. Shaft lock (9). 13. New shaft lock retaining ring (8) using J 23653-SIR to push down shaft lock (9). Ring (8) must be firmly seated in groove on shaft. 14. Shaft lock spacer (7). NOTICE: Set steering shaft so that block tooth on upper steering shaft (46) is at the 12 o'clock position, wheels on vehicle should be straight ahead, then set ignition switch to "LOCK" position, to ensure no damage to coil assembly (3). 15. Wave washer (4). NOTICE: Coil assembly (3) will become uncentered if: 1) Steering column is separated from steering gear and is allowed to rotate, or 2) Centering spring is pushed down, letting hub rotate while coil is removed from column. NOTICE: If a new coil assembly (3) is being installed, assemble pre-centered coil assembly (3) to steering column. Remove centering tab and Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 985 dispose. NOTICE: SIR coil assembly wire must be kept tight with no slack while installing SIR coil assembly. Failure to do so may cause wire to be kinked near shaft lock area and cut when steering wheel is turned. 16. Ensure coil assembly (3) hub is centered. 17. Coil assembly (3). a). Pull wires tight while positioning SIR coil to steering shaft. b). Align opening in coil with horn tower and "locating bump" between two tabs on housing cover. c). Seat coil assembly into steering column. d). Connector shroud (5). 18. Coil assembly retaining ring (2). Ring (2) must be firmly seated in groove on shaft. NOTICE: Gently pull lower coil assembly and turn signal harness to remove any wire kinks that may be inside steering column assembly. Failure to do so may cause damage to wire harness. 19. Wiring protector (43). 20. Negative (-) battery cable. 21. If all service operations are completed, enable the SIR system. Inspect a). Function check turn signal switch (15). b). Position switch lever to right turn position. Turn steering wheel to left. Switch should cancel to center position. c). Repeat above procedure for left turn position. d). If turn signal switch does not return to center position check switch (15) forbroken or missing cancel spring, or a worn or damaged cancel cam (10). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications Alignment: Technical Service Bulletins Steering/Suspension - Wheel Alignment Specifications WARRANTY ADMINISTRATION Bulletin No.: 05-03-07-009C Date: December 09, 2010 Subject: Wheel Alignment Specifications, Requirements and Recommendations for GM Vehicles Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks Supercede: This bulletin is being extensively revised to provide technicians and warranty administrators with an all inclusive guide for wheel alignments. PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. Please discard Corporate Bulletin Number 05-03-07-009B (Section 03 - Suspension). Purpose The purpose of this bulletin is to provide retail, wholesale and fleet personnel with General Motors' warranty service requirements and recommendations for customer concerns related to wheel alignment. For your convenience, this bulletin updates and centralizes all of GM's Standard Wheel Alignment Service Procedures, Policy Guidelines and bulletins on wheel alignment warranty service. Important PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. The following five (5) key steps are a summary of this bulletin and are REQUIRED in completing a successful wheel alignment service. 1. Verify the vehicle is in an Original Equipment condition for curb weight, tires, wheels, suspension and steering configurations. Vehicles modified in any of these areas are not covered for wheel alignment warranty. 2. Review the customer concern relative to "Normal Operation" definitions. 3. Verify that vehicle is within the "Mileage Policy" range. 4. Document wheel alignment warranty claims appropriately for labor operations E2000 and E2020. The following information must be documented or attached to the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 5. Use the proper wheel alignment equipment (preferred with print-out capability), process and the appropriate calibration maintenance schedules. Important If it is determined that a wheel alignment is necessary under warranty, use the proper labor code for the repair. E2000 for Steering Wheel Angle and/or Front Toe set or E2020 for Wheel Alignment Check/Adjust includes Caster, Camber and Toe set (Wheel alignment labor time for other component repairs is to be charged to the component that causes a wheel alignment operation.). The following flowchart is to help summarize the information detailed in this bulletin and should be used whenever a wheel alignment is performed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 991 Verify Original Equipment Condition of the Vehicle - Verify that Original Equipment Tires and Wheels or Official GM Accessory Tires and Wheels are on the vehicle. - Verify that aftermarket suspension "Lift" or "Lowering" Kits or other suspension alterations have NOT been done to the vehicle. - Check for accidental damage to the vehicle; for example, severe pothole or curb impacts, collision damage that may have affected the wheel alignment of the vehicle; e.g., engine cradles, suspension control arms, axles, wheels, wheel covers, tires may show evidence of damage/impact. - Check to be sure vehicle has seen "Normal Use" rather than abuse; e.g., very aggressive driving may show up by looking at the tires and condition of the vehicle. - Check for other additional equipment items that may significantly affect vehicle mass such as large tool boxes, campers, snow plow packages (without the snowplow RPO), etc., especially in trucks and cutaway/incomplete vehicles. Significant additional mass can affect trim height and wheel alignment of the vehicle and may necessitate a customer pay wheel alignment when placed semi-permanently in the vehicle (Upfitter instructions are to realign the vehicle after placement of these types of items. (This typically applies to trucks and incomplete vehicles that can be upfit with equipment such as the above.) Customer Concerns, "Normal Operation" Conditions and "Mileage Policy" Possible Concerns The following are typical conditions that may require wheel alignment warranty service: 1. Lead/Pull: defined as "at a constant highway speed on a typical straight road, the amount of effort required at the steering wheel to maintain the vehicle's straight heading." Important Please evaluate for the condition with hands-on the steering wheel. Follow the "Vehicle Leads/Pulls" diagnostic tree located in SI to determine the cause of a lead/pull concern. Lead/Pull concerns can be due to road crown or road slope, tires, wheel alignment or even in rare circumstances a steering gear issue. Lead/pull concerns due to road crown are considered "Normal Operation" and are NOT a warrantable condition -- the customer should be advised that this is "Normal Operation." Important Some customers may comment on a "Lead/Pull" when they hold the steering wheel in a level condition. If so, this is more likely a "steering wheel angle" concern because the customer is "steering" the vehicle to obtain a "level" steering wheel. 2. Steering wheel angle to the left or right (counter-clockwise or clockwise, respectively): Defined as the steering wheel angle (clocking) deviation from "level" while maintaining a straight heading on a typical straight road. 3. Irregular or Premature tire wear: Slight to very slight "feathering" or "edge" wear on the shoulders of tires is NOT considered unusual and should even out with a tire rotation; if the customer is concerned about a "feathering" condition of the tires, the customer could be advised to rotate the tires earlier than the next scheduled mileage/maintenance interval (but no later than the next interval). Be sure to understand the customer's driving habits as this will also heavily influence the tire wear performance; tire wear from aggressive or abusive driving habits is NOT a warrantable condition. Important Slight or mild feathering, cupping, edge or heel/toe wear of tire tread shoulders is "normal" and can show up very early in a tire/vehicle service mileage; in fact, some new tires can show evidence of feathering from the factory. These issues do NOT affect the overall performance and tread life of the tire. Dealer personnel should always check the customer's maintenance records to ensure that tire inflation pressure is being maintained to placard and that the tires are being rotated (modified-X pattern) at the proper mileage intervals. Wheel alignments are NOT to be performed for the types of "Normal" Tire Feathering shown in Figures 1-4 below. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 992 Figure 1: Full Tread View - "NORMAL" Tire "Feathering" Wear on the Shoulder/Adjacent/Center Ribs Figure 2: Tire Shoulder View Example 1 - "NORMAL" Tire "Feathering" Wear on the Shoulder Figure 3: Tire Shoulder View Example 2 - "NORMAL" Tire "Feathering" Wear Figure 4: Detail Side View of Tire Shoulder Area - "NORMAL" Tire "Feathering" Wear Important When a wheel alignment is deemed necessary for tire wear, be sure to document on the repair order, in as much detail as possible, the severity and type of tire wear (e.g., severe center wear or severe inside or outside shoulder wear) and the position of the tire on the vehicle (RF, LF, LR, RR). Please note the customer's concern with the wear such as, noise, appearance, wear life, etc. A field product report with pictures of the tire wear condition is recommended. Refer to Corporate Bulletin Number 02-00-89-002J and #07-00-89-036C. 4. Other repairs that affect wheel alignment; e.g., certain component replacement such as suspension control arm replacement, engine cradle adjustment/replace, steering gear replacement, steering tie rod replace, suspension strut/shock, steering knuckle, etc. may require a wheel alignment. Important If other components or repairs are identified as affecting the wheel alignment, policy calls for the wheel alignment labor time to be charged to the replaced/repaired component's labor operation time rather than the wheel alignment labor operations. Important Vibration type customer concerns are generally NOT due to wheel alignment except in the rare cases; e.g., extreme diagonal wear across the tread. In general, wheel alignments are NOT to be performed as an investigation/correction for vibration concerns. "Normal Operation" Conditions Vehicle Lead/Pull Due to Road Crown or Slope: As part of "Normal Operation," vehicles will follow side-to-side or left to right road crown or slope. Be sure to verify from the customer the types of roads they are driving as they may not recognize the influence of road crown on vehicle lead/pull and steering wheel angle. If a vehicle requires significant steering effort to prevent it from "climbing" the road crown there may be an issue to be looked into further. Important Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 993 A wheel alignment will generally NOT correct vehicles that follow the road crown since this is within "Normal Operation." Mileage Policy The following mileage policy applies for E2020 and E2000 labor operations: Note Wheel Alignment is NOT covered under the New Vehicle Limited Warranty for Express and Savana Cutaway vehicles as these vehicles require Upfitters to set the wheel alignment after completing the vehicles. - 0-800 km (0-500 mi): E2000/E2020 claims ONLY allowed with Call Center Authorization. Due to the tie down during shipping, the vehicle's suspension requires some time to reach normal operating position. For this reason, new vehicles are generally NOT to be aligned until they have accumulated at least 800 km (500 mi). A field product report should accompany any claim within this mileage range. - 801-12,000 km (501-7,500 mi): - If a vehicle came from the factory with incorrect alignment settings, any resulting off-angle steering wheel, lead/pull characteristics or the rare occurrence of excessive tire wear would be apparent early in the life of the vehicle. The following policy applies: - Vehicles 100% Factory Set/Measured for Caster/Camber/Toe - Escalade/ESV/EXT, Tahoe/Suburban, Yukon/XL/Denali, Silverado/Sierra, Express/Savana, Corvette and Colorado/Canyon: E2000/E2020 Claims: Call Center Authorization Required - All Vehicles NOT 100% Factory Set/Measured for Caster/Camber/Toe as noted above: E2000/E2020 Claims: Dealer Service Manager Authorization Required - 12,001 km and beyond (7,501 miles and beyond): During this period, customers are responsible for the wheel alignment expense or dealers may provide on a case-by case basis a one-time customer enthusiasm claim up to 16,000 km (10,000 mi). In the event that a defective component required the use of the subject labor operations, the identified defective component labor operation will include the appropriate labor time for a wheel alignment as an add condition to the component repair. Important Only one wheel alignment labor operation claim (E2000 or E2020) may be used per VIN. Warranty Documentation Requirements When a wheel alignment service has been deemed necessary, the following items will need to be clearly documented on/with the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 1. Document the customer concern in as much detail as possible on the repair order and in the warranty administration system. Preferred examples: - Steering wheel is off angle in the counterclockwise direction by approximately x degrees or clocking position. - Vehicle lead/pulls to the right at approximately x-y mph. Vehicle will climb the road crown. Severe, Moderate or Slight. - RF and LF tires are wearing on the outside shoulders with severe feathering. Important In the event of a lead/pull or steering wheel angle concern, please note the direction of lead/pull (left or right) or direction of steering wheel angle (clockwise or counterclockwise) on the repair order and within the warranty claim verbatim. Important In the event of a tire wear concern, please note the position on the vehicle and where the wear is occurring on the tire; i.e., the RF tire is wearing on the inside shoulder. 2. Document the technician's findings on cause and correction of the issue. Examples: - Reset LF toe from 0.45 degrees to 0.10 degrees and RF toe from -0.25 degrees to 0.10 degrees to correct the steering wheel angle from 5 degrees counterclockwise to 0 degrees. - Reset LF camber from 0.25 degrees to -0.05 degrees to correct the cross-camber condition of +0.30 degrees to 0.00 degrees on the vehicle. - Front Sum toe was found to be 0.50 degrees, reset to 0.20 degrees. 3. Print-out the "Before" and "After" wheel alignment measurements/settings and attach them to the Repair Order or if print-out capability is not Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 994 available, measurements may also be clearly and legibly handwritten into the Wheel Alignment Repair Order Questionnaire attached to this bulletin. 4. Attach the Wheel Alignment Repair Order Questionnaire below along with the print-out of "Before" and "After" wheel alignment measurements to the Repair Order and retain for use by GM. Wheel Alignment Equipment and Process Wheel alignments must be performed with a quality machine that will give accurate results when performing checks. "External Reference" (image-based camera technology) is preferred. Please refer to Corporate Bulletin Number 05-00-89-029B: General Motors Dealership Critical Equipment Requirements and Recommendations. Requirements: - Computerized four wheel alignment system. - Computer capable of printing before and after alignment reports. - Computer capable of time and date stamp printout. - Racking system must have jacking capability - Racking system must be capable of level to 1.6 mm (1/16 in) - Appropriate wheel stops and safety certification - Built-in turn plates and slip plates - Wheel clamps capable of attaching to 20" or larger wheels - Racking capable of accepting any GM passenger car or light duty truck - Operator properly trained and ASE-certified (U.S. only) in wheel alignment Recommendations: Racking should have front and rear jacking capability. Equipment Maintenance and Calibration: Alignment machines must be regularly calibrated in order to give correct information. Most manufacturers recommend the following: - Alignment machines with "internal reference" sensors should be checked (and calibrated, if necessary) every six months. - Alignment machines with "external reference" (image-based camera technology) should be checked (and calibrated, if necessary) once a year. - Racks must be kept level to within 1.6 mm (1/16 in). - If any instrument that is part of the alignment machine is dropped or damaged in some way, check the calibration immediately. Check with the manufacturer of your specific equipment for their recommended service/calibration schedule. Wheel Alignment Process When performing wheel alignment measurement and/or adjustment, the following steps should be taken: Preliminary Steps: 1. Verify that the vehicle has a full tank of fuel (compensate as necessary). 2. Inspect the wheels and the tires for damage. 3. Inspect the tires for the proper inflation and irregular tire wear. 4. Inspect the wheel bearings for excessive play. 5. Inspect all suspension and steering parts for looseness, wear, or damage. 6. Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components. 7. Inspect the vehicle trim height. 8. Compensate for frame angle on targeted vehicles (refer to Wheel Alignment Specifications in SI). Satisfactory vehicle operation may occur over a wide range of alignment angles. However, if the wheel alignment angles are not within the range of specifications, adjust the wheel alignment to the specifications. Refer to Wheel Alignment Specifications in SI. Give consideration to excess loads, such as tool boxes, sample cases, etc. Follow the wheel alignment equipment manufacturer's instructions. Measure/Adjust: Important Prior to making any adjustments to wheel alignment on a vehicle, technicians must verify that the wheel alignment specifications loaded into their wheel alignment machine are up-to-date by comparing these to the wheel alignment specifications for the appropriate model and model year in SI. Using incorrect and/or outdated specifications may result in unnecessary adjustments, irregular and/or premature tire wear and repeat customer concerns Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 995 Important When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front wheel alignment angles. Perform the following steps in order to measure the front and rear alignment angles: 1. Install the alignment equipment according to the manufacturer's instructions. 2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment. 3. Measure the alignment angles and record the readings. If necessary, adjust the wheel alignment to vehicle specification and record the before and after measurements. Refer to Wheel Alignment Specifications in SI. Important Technicians must refer to SI for the correct wheel alignment specifications. SI is the only source of GM wheel alignment specifications that is kept up-to-date throughout the year. Test drive vehicle to ensure proper repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 996 Frame Angle Measurement (Express / Savana Only) ........ Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 997 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Specifications > Vehicle Ride (Trim) Height Specifications Alignment: Specifications Vehicle Ride (Trim) Height Specifications Fig. 5 Vehicle Ride Height Refer to Fig. 5 for vehicle ride height measurements and specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Specifications > Vehicle Ride (Trim) Height Specifications > Page 1000 Alignment: Specifications Alignment Specifications Front Alignment Specifications Caster Angle, Degrees Limits [01] ............................................................................................................................................ ..................................................... +1.70 to +3.70 Desired [02] ........................................................... ...................................................................................................................................... +2.20 to 3.20 Camber Angle, Degrees ...................................................................................................................... ................................................................................. Limits Left [01] ................................................................................................................................................ ....................................................... 0 to +1.60 Right [01] .................................................................... ................................................................................................................................. 0 to +1.60 Desired Left [02] ................................................................................................................................................ .......................................... +.30 to +1.30 [02] Right [02] ..................................................................... ................................................................................................................... +.30 to +1.30 [02] Toe-In, Degrees [03] ............................................................................................................................ ............................................................. +.05 to +.15 Ball Joint Wear .................................................................................................................................... ......................................................................... [04] [01] Left and right side to be equal within 1.0 deg.. [02] Left and right side to be equal within 0.5 deg.. [03] Left & right toe-in is set separately at each wheel w/ steering wheel held in straight ahead position. [04] Refer to /Steering & Suspension/ Suspension/ Ball Joint/ Testing & Inspection. Rear Alignment Specifications Camber Angle, Degrees [01] Limits ................................................................................................................................................... .................................................................. -3 to +5 Desired ................................................................ ............................................................................................................................................................ 1 Toe Out, Degrees [01] ......................................................................................................................... ..................................................................... 0 to .05 [01] Camber & toe are not adjustable Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Service and Repair > Preliminary Inspection Alignment: Service and Repair Preliminary Inspection Inspect the following components, adjust, repair or replace as required prior to performing front wheel alignment. 1. Inflate tires to cold specifications. 2. Ensure front tires are of same size, ply rating and load rating. 3. Inspect for excessive wheel bearing endplay. 4. Inspect for worn or damaged spindle ball joints. 5. Inspect steering gear mounting bolts for proper torque. 6. Inspect radius arm for bent or damaged condition. 7. Inspect radius arm to frame bushings for looseness or wear. 8. Inspect for loose or broken shackles. 9. Inspect for distorted or split jounce bumper. 10. Inspect suspension components for wear or damage. 11. Inspect vehicle ride height. Refer to, Specifications/ Mechanical/ Vehicle Ride Height. 12. Ensure vehicle is on level surface when performing alignment procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Service and Repair > Preliminary Inspection > Page 1003 Alignment: Service and Repair Front Caster and Camber Adjustment Fig. 1 Caster & Camber Adjustment. CASTER & CAMBER Before checking and adjusting caster and camber angles, jounce front bumper at least three times, to allow vehicle to return to normal "trim height". This will prevent false readings. Caster and camber adjustments are made by adding, subtracting or transfer of shims inserted between upper control arm shaft and frame bracket, Fig. 1. To adjust caster and/or camber, loosen upper control arm shaft-to-frame nuts, then add or subtract shims as necessary to adjust, then tighten nuts to specifications. After adjustment, the shim pack should have at least two threads of bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 0.40 inch. When adjusting caster, transfer shims from front to rear or rear to front. The transfer of one shim from rear to front bolt will decrease positive caster. When adjusting camber, change shims equally at both front and rear of shaft. Adding an equal number of shims at front and rear will decrease positive camber. When performing either caster or camber adjustment, always tighten nut on thinner shim pack first to improve shaft-to-frame clamping force and torque retention. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Service and Repair > Preliminary Inspection > Page 1004 Alignment: Service and Repair Front Toe Adjustment Fig. 3 Tie Rod Adjuster Tube Fig. 4 Clamp & Sleeve Orientation TOE-IN To adjust toe-in, loosen clamp bolts at each end of steering tie rod adjusting sleeves. Replace the clamp bolts if the clamp bolt breakaway exceeds 80 inch lbs. With steering wheel in straight ahead position, turn tie rod adjusting sleeves to obtain proper adjustment. Decrease the length of the tie rod to increase toe-in. Increase the length of the tie rod to decrease the toe-in. After adjustment, check that number of threads showing on the inside of the adjusting sleeves are equal to within three and that the tie rod end stud lines up with steering knuckle. Position tie rod clamps and sleeves as shown in Figs. 3 and 4. Centerline of clamp bolt must be within 30 degrees of horizontal centerline. Torque nuts to 18 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Diagnostic Connector - Fuel Pump: Locations Engine Component Wiring, LH Side Located RH front of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations > Page 1010 C122, Fuel Pump Prime Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 1015 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 1016 Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Auto D 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 1017 Idle Speed: Adjustments CONTROLLED IDLE SPEED CHECK NOTE: Before performing this check, there should be no codes displayed, idle air control system has been checked and the ignition timing is correct. 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, refer to DIAGNOSIS BY SYMPTOM/DIAGNOSIS AND TESTING PROCEDURES/ROUGH, UNSTABLE OR INCORRECT IDLE. MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Man. N 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 1027 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 1033 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark 4.3L (M/L) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications > Page 1053 Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Locations Distributor And Coil 4.3L Engine Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation Distributor: Service and Repair Removal & Installation Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 1059 Distributor And Coil 4.3L Engine Distributor And Coil 5.0L And 5.7L (TBI) Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 1060 Distributor And Coil - 7.4L Engine Removal: NOTE:Verify ignition switch is "OFF". 1. Disconnect wiring harness connectors at side of distributor. 2. Remove coil wire and sparkplug wires on either the left or right side of the distributor. 3. Remove distributor cap by the two screws and set to side: A. Bring engine to TDC on the compression stroke for the #1 cylinder and align timing marks to 0~ . B. Scribe a mark on the distributor housing in line with the rotor. C. Scribe a mark on the engine in line with the rotor. D. Note position of the distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. Installation: NOTE:To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Install distributor and gasket (if applicable). 2. Install hold-down clamp and tighten bolt: ^ Bolt on the 2.8R to 35 Nm (26 lb. ft.). ^ Bolt on the 4.3Z, 5.0H, 5.7K & 7.4N to 35 Nm (25 lb. ft.) 3. Install distributor cap. 4. Connect wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 1061 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components Removal: 1. With distributor removed, disconnect wires at module terminals 2. Remove roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Remove gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Remove distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. Installation: 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 1062 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ............................................................... .045 inches Spark Plug Torque ............................................................................................................................... ..................................................... 15 Nm (11 lb. ft.) Spark Plug Type .................................................................................................................................. .............................................................. AC CR43TS NOTE: Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 1073 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 1074 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 1075 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics Drive Belt: Technical Service Bulletins Engine - Drive Belt Misalignment Diagnostics INFORMATION Bulletin No.: 08-06-01-008A Date: July 27, 2009 Subject: Diagnosing Accessory Drive Belt / Serpentine Belt Noise and Availability and Use of Kent-Moore EN-49228 Laser Alignment Tool - Drive Belt Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add a model year and update the Tool Information. Please discard Corporate Bulletin Number 08-06-01-008 (Section 06 - Engine). Background Several aftermarket companies offer laser alignment tools for accessory drive systems that can be very helpful in eliminating drive belt noise as a result of misaligned pulleys. Typically pricing ranges from $160 - $200. EN-49228 Laser Alignment Tool - Drive Belt The GM Tool program has now made available a competitive, simple to use and time-saving laser tool to assist in achieving precise alignment of the drive belt pulleys. This optional tool removes the guesswork from proper pulley alignment and may serve to reduce comebacks from: - Drive Belt Noise - Accelerated Drive Belt Wear - Drive Belt Slippage Instructions The instructions below are specific only to the truck Gen IV V-8 family of engines. These instructions are only for illustrative purposes to show how the tool may be used. Universal instructions are included in the box with the Laser Alignment Tool - Drive Belt. Caution - Do not look directly into the beam projected from the laser. - Use caution when shining the laser on highly polished or reflective surfaces. Laser safety glasses help reduce laser beam glare in many circumstances. - Always use laser safety glasses when using the laser. Laser safety glasses are not designed to protect eyes from direct laser exposure. 1. Observe and mark the serpentine belt orientation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1080 2. Remove the serpentine belt from the accessory drive system. 3. Install the tool onto the power steering pulley. Position the legs of the tool into the outer grooves of the pulley, farthest from the front of the engine. 4. Install the retaining cord around the pulley and to the legs of the tool. 5. Put on the laser safety glasses provided with the tool. 6. Depress the switch on the rear of the tool to activate the light beam. 7. Rotate the power steering pulley as required to project the light beam onto the crankshaft balancer pulley grooves. 8. Inspect for proper power steering pulley alignment. - If the laser beam projects onto the second rib or raised area (1), the pulleys are aligned properly. - If the laser beam projects more than one-quarter rib 0.9 mm (0.035 in) mis-alignment, adjust the position of the power steering pulley as required. - Refer to SI for Power Steering Pulley Removal and Installation procedures. 9. Install the serpentine belt to the accessory drive system in the original orientation. 10. Operate the vehicle and verify that the belt noise concern is no longer present. Tool Information Please visit the GM service tool website for pricing information or to place your order for this tool. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1081 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1082 Drive Belt: Technical Service Bulletins Engine - Serpentine Drive Belt Wear Information Bulletin No.: 04-06-01-013 Date: April 29, 2004 INFORMATION Subject: Information on Serpentine Belt Wear Models: 2004 and Prior Passenger Cars and Trucks 2003-2004 and Prior HUMMER H2 All current GM vehicles designed and manufactured in North America were assembled with serpentine belts that are made with an EPDM material and should last the life of the vehicle. It is extremely rare to observe any cracks in EPDM belts and it is not expected that they will require maintenance before 10 years or 240,000 km (150,000 mi) of use. Older style belts, which were manufactured with a chloroprene compound, may exhibit cracks depending on age. However, the onset of cracking typically signals that the belt is only about halfway through its usable life. A good rule of thumb for chloroprene-based belts is that if cracks are observed 3 mm (1/8 in) apart, ALL AROUND THE BELT, the belt may be reaching the end of its serviceable life and should be considered a candidate for changing. Small cracks spaced at greater intervals should not be considered as indicative that the belt needs changing. Any belt that exhibits chunking should be replaced. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Page 1083 Drive Belt: Service and Repair Fig. 17 Serpentine Drive Belt Routing 1. Insert a 1/2 inch breaker bar into the tensioner pulley. 2. Rotate tensioner counterclockwise, then remove drive belt. 3. Route drive belt over all pulleys except water pump, Fig. 17. 4. Insert a 1/2 inch breaker bar into the tensioner pulley. 5. Rotate tensioner counterclockwise then slip belt over water pump pulley. 6. Ensure proper belt tracking around each pulley. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 1094 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON > Page 1100 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 00-07-30-022D > Jun > 08 > A/T 4L60/65E, No Reverse/2nd or 4th Gear Sun Gear: All Technical Service Bulletins A/T - 4L60/65E, No Reverse/2nd or 4th Gear TECHNICAL Bulletin No.: 00-07-30-022D Date: June 10, 2008 Subject: No Reverse, Second Gear or Fourth Gear (Replace Reaction Sun Shell with More Robust Heat Treated Parts) Models: 1993 - 2005 GM Passenger Cars and Light Duty Trucks 2003 - 2005 HUMMER H2 with 4L60/65-E Automatic Transmission (RPOs M30 or M32) Supercede: This bulletin is being revised to add 2005 model year to the parts information. Please discard Corporate Bulletin Number 00-07-30-022C (Section 07 - Transmission/Transaxle). Condition Some customers may comment on a no reverse, no second or no fourth gear condition. First and third gears will operate properly. Cause The reaction sun gear (673) may not hold inside the reaction sun shell (670). Correction Important: There are FOUR distinct groups of vehicles and repair procedures involved. Vehicles built in the 2001 model year and prior that make use of a reaction shaft to shell thrust washer: ^ The sun shell can be identified by four square holes used to retain the thrust washer. Use reaction sun shell P/N 24228345, reaction carrier to shell thrust washer (699B) P/N 8642202 and reaction sun gear shell thrust washer (674) P/N 8642331er (674) P/N 8642331along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and prior that have had previous service to the reaction sun shell: It is possible that some 2001 and prior model year vehicles have had previous service to the reaction sun shell. At the time of service, these vehicles may have been updated with a Reaction Sun Shell Kit (Refer to Service Bulletin 020730003) without four square holes to retain the thrust washer. If it is found in a 2001 model year and prior vehicles that the reaction sun shell DOES NOT have four square holes to retain the thrust washer, these vehicles must be serviced with P/Ns 24229825 (674), 24217328 and 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and later that make use of a reaction shaft to shell thrust bearing: The sun shell can be identified by no holes to retain the thrust washer. Use reaction sun shell, P/N 24229825, reaction carrier shaft to shell thrust bearing (669A), P/N 24217328 and reaction sun gear shell thrust washer (674), P/N 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built from November, 2001 through June, 2002: These vehicles should have the reaction carrier shaft replaced when the sun shell is replaced. Use shell kit P/N 24229853, which contains a sun shell (670), a reaction carrier shaft (666), a reaction carrier shaft to shell thrust bearing (669A) and a reaction sun gear shell thrust washer (674). The appropriate seals and washers listed below should also be used. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Follow the service procedure below for diagnosis and correction of the no reverse, no second, no forth condition. Important: If metallic debris is found on the transmission magnet, the transmission must be completely disassembled and cleaned. Metallic debris is defined as broken parts and pieces of internal transmission components. This should not be confused with typical "normal" fine particles found on all transmission magnets. Failure to properly clean the transmission case and internal components may lead to additional repeat repairs. 1. Remove the transmission oil pan and inspect the magnet in the bottom of the pan for metal debris. Refer to SI Document ID # 825141. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 00-07-30-022D > Jun > 08 > A/T 4L60/65E, No Reverse/2nd or 4th Gear > Page 1106 2. Remove the transmission from the vehicle. Refer to the appropriate SI document. Important: ^ Inspect all the transmission components for damage or wear. Replace all damaged or worn components. The parts shown above should be sufficient to correct this concern. ^ This condition does not normally require replacement of the transmission completely. Components such as clutches, valve body, pump and torque converters will NOT require replacement to correct this condition. Disassemble the transmission and replace the appropriate parts listed below. Refer to the Unit Repair Manual - Repair Instructions. 3. Reinstall the transmission in the vehicle. Refer to appropriate service information. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 00-07-30-022D > Jun > 08 > A/T 4L60/65E, No Reverse/2nd or 4th Gear > Page 1107 Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 00-07-30-022D > Jun > 08 > A/T 4L60/65E, No Reverse/2nd or 4th Gear > Page 1113 2. Remove the transmission from the vehicle. Refer to the appropriate SI document. Important: ^ Inspect all the transmission components for damage or wear. Replace all damaged or worn components. The parts shown above should be sufficient to correct this concern. ^ This condition does not normally require replacement of the transmission completely. Components such as clutches, valve body, pump and torque converters will NOT require replacement to correct this condition. Disassemble the transmission and replace the appropriate parts listed below. Refer to the Unit Repair Manual - Repair Instructions. 3. Reinstall the transmission in the vehicle. Refer to appropriate service information. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 00-07-30-022D > Jun > 08 > A/T 4L60/65E, No Reverse/2nd or 4th Gear > Page 1114 Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Crankcase Filter > Component Information > Service and Repair Crankcase Filter: Service and Repair The PCV system should be checked every 15,000 miles and also during regular engine tune-ups. If the PCV system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the PCV valve or air cleaner is replaced. When a periodic inspection indicates the PCV is not functioning properly, it should be serviced by replacement only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Evaporative Canister Filter > Component Information > Service and Repair Evaporative Canister Filter: Service and Repair NOTE: NOT ALL EVAPORATIVE EMISSION CONTROL CANISTERS HAVE A SERVICEABLE FILTER. At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, 1. Remove all hoses from the top of the canister and mark. Remove the canister. 2. Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. 3. Squeeze the new element under retainer bar, where used, and position it evenly around the entire bottom of the canister. Tuck the edges under the lip of canister. 4. Reinstall the canister to its original position on the vehicle, following normal service procedures. 5. Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal Fluid Filter - A/T: Technical Service Bulletins A/T - Updated Design Oil Filter Assembly & Seal Group Ref.: Transmission Bulletin No.: 377142A Date: February, 1994 INFORMATION SUBJECT: NEW TRANSMISSION OIL FILTER ASSEMBLY MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K AND S/T TRUCKS 1994 CHEVROLET AND GMC M/L AND G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (M30) THIS BULLETIN IS BEING REVISED TO CLARIFY TRANSMISSION USAGE. PLEASE DISCARD BULLETIN 377142. BULLETIN COVERS: New product information for 1994 HYDRA-MATIC 4L60-E transmissions. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal > Page 1125 DATE OF PRODUCTION CHANGE: (Figure 1 and 2) On August 10, 1993 (Julian Date 222), HYDRA-MATIC 4L60-E transmissions were built with a new filter seal (ill. 71) and transmission oil filter assembly (ill. 72). The previous transmission oil filter assembly and filter seal had an assembly method of installing the seal on the filter neck and then installing the filter in the transmission. When using the new filter seal and transmission oil filter assembly, the filter seal must be installed in the transmission first and then install the transmission oil filter assembly into the transmission. NOTE: The new filter seal and transmission oil filter assembly can be used on all HYDRA-MATIC 4L60-E transmissions 1993-1994. The new filter seal and transmission oil filter assembly cannot be used on any HYDRA-MATIC 4L60 transmission. The new filter seal cannot be used with the old transmission oil filter assembly and the new transmission oil filter assembly cannot be used with the old filter seal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1142 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1143 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1144 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1145 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1146 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1147 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1148 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1162 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1163 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1164 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1165 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1166 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1167 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1168 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Locations > Heater Hose Routing Heater Hose: Locations Heater Hose Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 1187 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 1188 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 1189 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 1190 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Brake Fluid > Component Information > Technical Service Bulletins > Brake Fluid - Level & Filling Recommendations Brake Fluid: Technical Service Bulletins Brake Fluid - Level & Filling Recommendations File In Section: 05 - Brakes Bulletin No.: 00-05-22-004 Date: May, 2000 INFORMATION Subject: Brake Fluid Level and Filling Recommendations Models: 2001 and Prior Passenger Cars and Trucks Many dealers and after-market repair shops advertise multi-point fluid "top-ups" in conjunction with oil changes or regular maintenance packages. These offers often include adding brake fluid to the master cylinder reservoir. There are only two reasons why the brake fluid level in the brake reservoir might go down. The first is that the brake fluid level goes down an acceptable level during normal brake lining wear. When the linings are replaced, the fluid will return to it's original level. The second possible reason for a low fluid level is that fluid is leaking out of the brake system. If fluid is leaking, the brake system requires repair and adding additional fluid will not correct the leak. If the system was properly filled during delivery of the vehicle, no additional fluid should be required under most circumstances between brake pad and/or shoe replacements. This information can be reinforced with the customer by referring them to the Brake Fluid section of their vehicle's Owner's Manual. Guidelines GM vehicles have incorporated a variety of brake fluid reservoir styles. The following guidelines are restricted to the plastic bodied fluid reservoirs and do not affect the original service recommendations for the older style metal bodied units. You may encounter both black plastic and translucent style reservoirs. You may have reservoirs with: ^ A MAX fill mark only ^ A MIN fill mark only ^ Both MAX and MIN marks The translucent style reservoirs do not have to have the covers removed in order to view the fluid level. It is a good practice not to remove the reservoir cover unless necessary to reduce the possibility of contaminating the system. Use the following guidelines to assist in determining the proper fluid level. Important: When adding brake fluid, use Delco Supreme II(R) Brake Fluid, GM P/N 12377967 or equivalent brand bearing the DOT-3 rating only. Important: At no time should the fluid level be allowed to remain in an overfilled condition. Overfilling the brake reservoir may put unnecessary stress on the seals and cover of the reservoir. Use the following guidelines to properly maintain the fluid level. If the reservoir is overfilled, siphon out the additional fluid to comply with the guidelines below. Important: If under any circumstance the brake fluid level is extremely low in the reservoir or the BRAKE warning indicator is illuminated, the brake system should be checked for leaks and the system repaired in addition to bringing the fluid level up to the recommended guidelines outlined below. A leaking brake system will have reduced braking performance and will eventually not work at all. Important: Some vehicles have reservoirs that are very sensitive to brake fluid levels and may cause the BRAKE indicator to flicker on turns as the fluid approaches the minimum required level. If you encounter a vehicle with this concern, increase the fluid level staying within the guidelines outlined below. ^ If the reservoir has a MAX level indicator, the reservoir should be returned to the MAX marking only at the time new brake pads and/or shoes are installed. If the reservoir fluid level is at the half-way point or above do not attempt to add additional brake fluid during routine fluid checks. ^ If the reservoir has both MAX and MIN indicators, the fluid level should be maintained above the MIN indicator during routine fluid checks and returned to the MAX indication only after new brake pads and/or shoes are installed. ^ For reservoirs with only a MIN indication, the fluid level should be maintained above the MIN indicator during routine fluid checks. Return the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Brake Fluid > Component Information > Technical Service Bulletins > Brake Fluid - Level & Filling Recommendations > Page 1196 reservoir fluid level to full only after installing new brake pads and/or shoes. A full reservoir is indicated on translucent, snap cover reservoirs by a fluid level even with the top level of the view window imprinted into the side of the reservoir. On screw top models in black or translucent plastic, the full level is just below the bottom of the filler neck. Parts Information Part Number Description 12377967 Brake Fluid Parts are currently available from GMSPO. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Brake Fluid > Component Information > Technical Service Bulletins > Page 1197 Brake Fluid: Specifications Brake System DOT 3 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Clutch Fluid > Component Information > Specifications > Capacity Specifications Clutch Fluid: Capacity Specifications Fill the clutch master cylinder to the "Full" or "MAX" mark on the reservoir. Do not overfill. Caution: Should accidental spillage occur, rinse the area thoroughly with water. Pay special attention to any electrical wires, parts, harnesses, rubber or painted surfaces. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Clutch Fluid > Component Information > Specifications > Capacity Specifications > Page 1202 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information Coolant: Technical Service Bulletins Cooling System - Coolant Recycling Information Bulletin No.: 00-06-02-006D Date: August 15, 2006 INFORMATION Subject: Engine Coolant Recycling and Warranty Information Models: 2007 and Prior GM Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER Vehicles 2005-2007 Saab 9-7X Attention: Please address this bulletin to the Warranty Claims Administrator and the Service Manager. Supercede: This bulletin is being revised to adjust the title and Include Warranty Information. Please discard Corporate Bulletin Number 00-06-02-006C (Section 06 - Engine/Propulsion System). Coolant Reimbursement Policy General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words: if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of GM Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Licensed Approved DEX-COOL(R) Providers Important: USE OF NON-APPROVED VIRGIN OR RECYCLED DEX-COOL(R) OR DEVIATIONS IN THE FORM OF ALTERNATE CHEMICALS OR ALTERATION OF EQUIPMENT, WILL VOID THE GM ENDORSEMENT, MAY DEGRADE COOLANT SYSTEM INTEGRITY AND PLACE THE COOLING SYSTEM WARRANTY UNDER JEOPARDY. Shown in Table 1 are the only current licensed and approved providers of DEX-COOL(R). Products that are advertised as "COMPATIBLE" or "RECOMMENDED" for use with DEX-COOL(R) have not been tested or approved by General Motors. Non-approved coolants may degrade the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1207 coolant system integrity and will no longer be considered a 5 yr/150,000 mile (240,000 km) coolant. Coolant Removal Services/Recycling The tables include all coolant recycling processes currently approved by GM. Also included is a primary phone number and demographic information. Used DEX-COOL(R) can be combined with used conventional coolant (green) for recycling. Depending on the recycling service and/or equipment, it is then designated as a conventional 2 yr/30,000 mile (50,000 km) coolant or DEX-COOL(R) 5 yr/150,000 mile (240,000 km) coolant. Recycled coolants as designated in this bulletin may be used during the vehicle(s) warranty period. DEX-COOL(R) Recycling The DEX-COOL(R) recycling service listed in Table 2 has been approved for recycling waste engine coolants (DEX-COOL) or conventional) to DEX-COOL(R) with 5 yr/150,000 mile (240,000 km) usability. Recycling Fluid Technologies is the only licensed provider of Recycled DEX-COOL(R) meeting GM6277M specifications and utilizes GM approved inhibitor packages. This is currently a limited program being monitored by GM Service Operations which will be expanded as demand increases. Conventional (Green) Recycling Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1208 Processes shown in the Table 3 are capable of recycling waste engine coolants (DEX-COOL(R) or conventional) to a conventional (green) coolant. Recycling conventional coolant can be accomplished at your facility by a technician using approved EQUIPMENT (listed by model number in Table 3), or by an approved coolant recycling SERVICE which may recycle the coolant at your facility or at an offsite operation. Refer to the table for GM approved coolant recyclers in either of these two categories. Should you decide to recycle the coolant yourself, strict adherence to the operating procedures is imperative. Use ONLY the inhibitor chemicals supplied by the respective (GM approved) recycling equipment manufacturer. Sealing Tablets Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage. Water Quality The integrity of the coolant is dependent upon the quality of DEX-COOL(R) and water. DEX-COOL(R) is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL(R) with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL(R). "Pink" DEX-COOL(R) DEX-COOL(R) is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL(R), some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval. Back Service Only use DEX-COOL(R) if the vehicle was originally equipped with DEX-COOL(R). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1209 Contamination Mixing conventional green coolant with DEX-COOL(R) will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL(R) and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL(R). After 5 years/150,000 miles (240,000 km) After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL(R) and has not had problems with contamination from non-DEX-COOL(R) coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km) Equipment (Coolant Exchangers) The preferred method of performing coolant replacement is to use a coolant exchanger. A coolant exchanger can replace virtually all of the old coolant with new coolant. Coolant exchangers can be used to perform coolant replacement without spillage, and facilitate easy waste collection. They can also be used to lower the coolant level in a vehicle to allow for less messy servicing of cooling system components. It is recommended that you use a coolant exchanger with a vacuum feature facilitates removing trapped air from the cooling system. This is a substantial time savings over repeatedly thermo cycling the vehicle and topping-off the radiator. The vacuum feature also allows venting of a hot system to relieve system pressure. Approved coolant exchangers are available through the GMDE (General Motors Dealer Equipment) program. For refilling a cooling system that has been partially or fully drained for repairs other than coolant replacement, the Vac-N-Fill Coolant Refill Tool (GE-47716) is recommended to facilitate removal of trapped air from the cooling system during refill. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1210 Coolant: Technical Service Bulletins Engine Coolant - Information on Back Service File In Section: 6 - Engine Bulletin No: 53-62-02 Date: November, 1995 Subject: DEX-COOL(TM) Engine Coolant - Information on Back service Models: 1994-95 Passenger Cars and Trucks A new extended-life engine coolant called DEX-COOL(TM) is currently being used in all General Motors' vehicles (excluding Chevrolet Geo and Saturn). Refer to bulletin 53-62-01 for general service information. Backservice DEX-COOL(TM) may be used in General Motors vehicles originally built with conventional (green) coolant with the following considerations: ^ Vehicles eligible for back service are 1994 and 1995 models (excluding 1994 J Body with 4 cylinder engines). ^ The service interval for DEX-COOL(TM) introduced into an older model vehicle originally built with "green" coolant will be 2 years/30,000 miles (50,000 Km) (not 5 years/100,000 miles (160,000 Km)). ^ All the "green" coolant must be removed from the cooling system by means of a system flush. This may be accomplished with a water flushing device or a GMDE waterless coolant changer (use a unit dedicated to "green" coolant, not DEX-COOL TM). Important: When using a GMDE waterless coolant changer, conduct the procedure twice, once with water, and once with DEX-COOL(TM) Backservice with DEX-COOL(TM) is advocated because of enhanced water pump seal durability experienced with this coolant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1211 Coolant: Technical Service Bulletins Warranty - Recycled Engine Coolant Policy Group Ref.: Warranty Administration Bulletin No.: 310504 Date: February, 1994 WARRANTY ADMINISTRATION SUBJECT: RECYCLED ENGINE COOLANT POLICY MODELS: 1994 AND PRIOR PASSENGER CARS AND TRUCKS ATTENTION: WARRANTY CLAIMS ADMINISTRATOR AND SERVICE MANAGER General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. For detailed information on GM approved engine coolant recycling equipment guidelines refer to the following bulletins: Cadillac 93-1-18, GMC Truck 93-6B-34, Chevrolet 93-73-6B, Pontiac 93-6-18, Oldsmobile 1-93-43, Buick 93-6B-1 (Corporate Number 236203). Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial to assure that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words, if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1212 Coolant: Technical Service Bulletins Coolant - Information on Propylene Glycol Usage File In Section: 6 - Engine Bulletin No.: 43-62-01B Date: April, 1995 Subject: Propylene Glycol Engine Coolant Models: 1994 and Prior Passenger Cars and Trucks This bulletin is being revised to reflect most current information on propylene glycol engine coolant. Please discard Corporate Bulletin Number 4362O1A (Group Reference 6 - Engine). General Motors has been reviewing data supplied on the performance of propylene glycol engine coolant in GM vehicles. It is our conclusion that propylene glycol engine coolant will perform adequately under most vehicle operating conditions. As a result, propylene glycol engine coolant (meeting performance specification GM 1825M) may be used in GM vehicles and will not affect the warranty coverage. Prior to adding propylene glycol engine coolant to the cooling system, all the existing (ethylene glycol) coolant must be removed. This can be accomplished either by utilizing water-based coolant flushing equipment or "waterless quick change" equipment available in the GMDE program. As with any coolant change procedure, be sure to thoroughly purge the heater core and block as well as the radiator before attempting to convert the system to propylene glycol coolant. Freeze/Boil point levels are different for propylene glycol than for ethylene glycol engine coolant. To accurately determine freeze/boil protection level, it is imperative that coolants not be mixed. Removing all the used coolant as previously discussed resolves this concern. Freeze protection of propylene glycol cannot be determined using a standard hydrometer. Rather, a refractometer or test strip must be used. Propylene glycol engine coolants may be recycled in the same manner as conventional ethylene glycol coolant. No adverse effects will be encountered if these coolants are mixed prior to recycling, however, the ratio of propylene glycol coolant to ethylene glycol coolant should be kept low to minimize the effects on freeze point measurements. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Page 1213 Coolant: Specifications Coolant Capacity, Qts. Less A/C [03] ....................................................................................................................................... ....................................................................... 13.5 With A/C [03] ....................................................... ...................................................................................................................................................... 13.5 Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 [03] Add 3.0 qts. if equipped w/ rear heater. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: Technical Service Bulletins A/T - DEXRON(R)-VI Fluid Information INFORMATION Bulletin No.: 04-07-30-037E Date: April 07, 2011 Subject: Release of DEXRON(R)-VI Automatic Transmission Fluid (ATF) Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks 2003-2008 HUMMER H2 2006-2008 HUMMER H3 2005-2007 Saturn Relay 2005 and Prior Saturn L-Series 2005-2007 Saturn ION 2005-2008 Saturn VUE with 4T45-E 2005-2008 Saab 9-7X Except 2008 and Prior Chevrolet Aveo, Equinox Except 2006 and Prior Chevrolet Epica Except 2007 and Prior Chevrolet Optra Except 2008 and Prior Pontiac Torrent, Vibe, Wave Except 2003-2005 Saturn ION with CVT or AF23 Only Except 1991-2002 Saturn S-Series Except 2008 and Prior Saturn VUE with CVT, AF33 or 5AT (MJ7/MJ8) Transmission Only Except 2008 Saturn Astra Attention: DEXRON(R)-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids. Supercede: This bulletin is being revised to update information. Please discard Corporate Bulletin Number 04-07-30-037D (Section 07 - Transmission/Transaxle). MANUAL TRANSMISSIONS / TRANSFER CASES and POWER STEERING The content of this bulletin does not apply to manual transmissions or transfer cases. Any vehicle that previously required DEXRON(R)-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid. Some manual transmissions and transfer cases require a different fluid. Appropriate references should be checked when servicing any of these components. Power Steering Systems should now use P/N 9985010 labeled Power Steering Fluid. Consult the Parts Catalog, Owner's Manual, or Service Information (SI) for fluid recommendations. Some of our customers and/or General Motors dealerships/Saturn Retailers may have some concerns with DEXRON(R)-VI and DEXRON(R)-III Automatic Transmission Fluid (ATF) and transmission warranty claims. DEXRON(R)-VI is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids (except as noted above). Please remember that the clean oil reservoirs of the J-45096 - Flushing and Flow Tester machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI for testing, flushing or filling General Motors transmissions/transaxles (except as noted above). DEXRON(R)-VI can be used in any proportion in past model vehicles equipped with an automatic transmission/transaxle in place of DEXRON(R)-III (i.e. topping off the fluid in the event of a repair or fluid change). DEXRON(R)-VI is also compatible with any former version of DEXRON(R) for use in automatic transmissions/transaxles. DEXRON(R)-VI ATF General Motors Powertrain has upgraded to DEXRON(R)-VI ATF with the start of 2006 vehicle production. Current and prior automatic transmission models that had used DEXRON(R)-III must now only use DEXRON(R)-VI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1218 All 2006 and future model transmissions that use DEXRON(R)-VI are to be serviced ONLY with DEXRON(R)-VI fluid. DEXRON(R)-VI is an improvement over DEXRON(R)-III in the following areas: * These ATF change intervals remain the same as DEXRON(R)-III for the time being. 2006-2008 Transmission Fill and Cooler Flushing Some new applications of the 6L80 six speed transmission will require the use of the J 45096 Flushing and Flow Tester to accomplish transmission fluid fill. The clean oil reservoir of the machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI. Parts Information Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1219 Fluid - A/T: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1220 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1221 Fluid - A/T: Technical Service Bulletins A/T - Dexron IIE Preferred Fluid for All Hydra-matic BULLETIN No.: 9274T60-E-02 CORP. REF. NO.: 177125 DATE: October 1991 TRANSMISSION APPLICATIONS: All TRANSMISSION MODELS: All SUBJECT: Dexron(R)-IIE Automatic Transmission/Transaxle Fluid VEHICLE APPLICATIONS: All Hydra-matic Automatic Transmissions/Transaxles BULLETIN COVERS: General Motors has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON(R)-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmissions/transaxles and will eventually replace DEXRON(R)-II. DEXRON(R)-IIE is acceptable for use whenever DEXRON(R)-II was previously specified. DEXRON(R)-II is acceptable for use when DEXRON(R)-IIE is not available. DEXRON(R)-II and DEXRON(R)-IIE can be used in both electronically and hydraulically controlled transmissions/ transaxles. DEXRON(R)-IIE Advantages Over DEXRON(R)-II: ^ Has better anti-foaming characteristic. ^ Improved high temperature oxidation stability and improved low temperature flow characteristics (low temperature viscosity). ^ DEXRON(R)-IIE and DEXRON(R)-II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON(R)-IIE is back serviceable to 1949 for all General Motors automatic transmissions/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON(R)-IIE. SERVICE PART INFORMATION: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1222 Fluid - A/T: Technical Service Bulletins A/T - DEXRON III Fluid Introduction File In Section: 0 - General Information Bulletin No.: 57-02-01 Date: March, 1995 SERVICE MANUAL UPDATE Subject: Section 0 - General Information - DEXRON(R)-III Transmission Fluid Introduction Models: 1995 and Prior Passenger Cars and Trucks General Motors has phased in a new automatic transmission fluid, DEXRON(R)-III, that does not need replacing under normal service. DEXRON(R)-III is designed to help the transmission deliver the best possible performance under all conditions. Refer to Figure 1. The improvements in DEXRON(R)-III include better friction stability, more high temperature oxidation stability and better material compatibility. DEXRON(R)-III has the same low temperature fluidity as DEXRON(R)-IIE, for better transmission performance in cold weather. DEXRON(R)-IIE and DEXRON(R)-III are fully compatible. DEXRON(R)-III is fully compatible with any General Motors passenger vehicle or light truck with automatic transmission and built since 1949. Dealers should require their supplier to include the DEXRON(R)-III license number on all automatic transmission fluid invoices. Starting February 1, 1994 DEXRON(R)-III was phased into all North American assembly plants. DEXRON(R)-III fluid is available from GMSPO (see fluid numbers below): U.S. 1 Quart 12346143 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1223 1 Gallon 12346144 55 Gallon 12346145 In Canada 1 Liter 10952622 4 Liter 10952623 200 Liter 10952624 The 1995 Automatic Transmission/Transaxle fluid change intervals are the following: (1994 and prior should use the schedules as written in the Owner's Manual.) If the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police car or delivery service. Change the fluid and filter every 50,000 miles (63,000 km). If the vehicle is not used mainly under any of these conditions, the fluid and filter do not require periodic changing for vehicles under 8,600 GVWR. Vehicles over 8,600 GVWR change the fluid and filter every 50,000 miles (83,000 km) regardless of driving conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Specifications > Capacity Specifications Fluid - A/T: Capacity Specifications CAPACITIES ....................................................................................................................................... ................................................................ QUARTS Pan Capacity ....................................................................................................................................... .............................................................................. 5.0 Total (Overhaul) Capacity ............................... .............................................................................................................................................................. .. 11.2 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Specifications > Capacity Specifications > Page 1226 Fluid - A/T: Fluid Type Specifications Fluid Type ............................................................................................................................................ ............................................................... Dexron IIE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Specifications > Page 1227 Fluid - A/T: Testing and Inspection Fluid level should be checked at every engine oil change. Frequency of change for transmission fluid is dependent on the type of driving conditions in which the vehicle is used. If the transmission is subjected to severe service such as: use in heavy city traffic when the outside temperature regularly reaches 90°F, use in very hilly or mountainous areas, commercial use such as taxi or delivery service, the fluid should be changed every 15,000 miles when using Dexron II and 50,000 miles when using Dexron III or equivalent. Otherwise, change the fluid every 100,000 miles, using Dexron II, III or equivalent automatic transmission fluid. When checking fluid, ensure vehicle is at operating temperature (190°-200°F), which can be obtained by 15 miles of highway-type driving. After transmission fluid is at operating temperature, use the following procedure to check fluid level: 1. Ensure vehicle is on a level surface, then move gear selector to the Park position. 2. Apply parking brake and block wheels, then allow engine to run at idle speed for three minutes with accessories off. 3. Check fluid level, color and condition. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Service and Repair > Changing Fluid Fluid - A/T: Service and Repair Changing Fluid 1. Raise and support vehicle. 2. Loosen two bolts attaching right side of transmission support to frame rail. 3. Remove two bolts attaching left side transmission support to frame rail. 4. Using suitable transmission jack, support and slightly raise transmission. 5. Slide transmission support rearward enough to access rear oil pan attaching bolts. 6. Place drain pan under transmission oil pan, loosen pan bolts on front of pan, pry carefully with screwdriver to loosen oil pan, and allow fluid to drain. 7. Remove remaining oil pan bolts, oil pan, and gasket. 8. Drain fluid from pan, then clean pan and dry thoroughly with compressed air. 9. Remove oil filter to valve body bolt, then remove filter and gasket, replace with new filter and gasket. 10. Install new gasket on oil pan, then oil pan and attaching bolts. Tighten attaching bolts to specification. 11. Lower vehicle and add five quarts of automatic transmission fluid through filler tube. 12. With selector lever in Park and parking brake applied, start engine and let idle. Do not race engine. 13. Move selector lever through each gear range, then return lever to park. 14. Check fluid, then add additional fluid to bring level between dimples on dipstick. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Service and Repair > Changing Fluid > Page 1230 Fluid - A/T: Service and Repair Adding Fluid to A DRY Transmission 1. Add transmission fluid through filler tube until oil level is between the "ADD" and "HOT" marks on dipstick. 2. Place selector lever in park, depress accelerator to place carburetor on fast idle cam, and move selector lever through each range. Do not race engine. 3. With selector lever in park, engine running at idle (1-3 minutes), and vehicle on level surface, check fluid level and add additional fluid to bring level between dimples on dipstick. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - M/T > Component Information > Specifications Fluid - M/T: Specifications TYPE: Astro/Safari .......................................................................................................................................... ...............................................................................AF S-Series 5-speed sectional case, RPO MY2 (NV3500) ....................................................................................................................................................GLS S-Series, others ................................................................................................................................... ................................................................................AF CAPACITY, Initial Fill: Astro, Safari: 4-speed 1987........................................................................................................................................ ...........................................2.3 Liters 4.9 Pints 5-speed 1987-90......................................................... .....................................................................................................................2.0 Liters 4.4 Pints S-Series: 4-speed Isuzu w/one piece bell housing trans. case 1987............................................................................................................... ........................................2.3 Liters 4.9 Pints 4-speed w/top load............................................................................................................................... ............................................2.0 Liters 4.2 Pints 5-speed top cover: 1987-91................................................................................................................................................ .........2.0 Liters 4.2 Pints 1992-94......................................................................................................... ................................................2.8 Liters 5.9 Pints 5-speed sectional cover........................................................................................................................ ............................................1.9 Liters 4.0 Pints Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage Fluid - Differential: Technical Service Bulletins Drivetrain - Rear Axle Lubricant Compatibility & Usage File in Section: 04 - Driveline Axle Bulletin No.: 99-04-20-001 Date: June, 1999 INFORMATION Subject: Rear Axle Lubricant Compatibility and Usage Models: 1999 Cadillac Escalade 1988-99 Chevrolet and GMC C/K, G Van and P1-3 Series Models Built after the VIN Breakpoints (C/K) listed. This bulletin is being revised to add the 1999 Model Year, VIN Breakpoint information, and additional text Please discard Corporate Bulletin Number 86-42-04 (Section 4 - Driveline/Axle). This bulletin is being issued to inform dealers about the compatibility and usage of the new Fuel Efficient SAE 75W-90 Synthetic Axle Lubricant, GM P/N 12378261 (In Canada use P/N 10953455), with current axles, and with the non-synthetic axle lubricant, GM P/N 1052271 (In Canada use P/N 10950849), for the rear axles on the above light-duty trucks. Testing has shown that the new synthetic lubricant will chemically attack the Room Temperature Vulcanizing (RTV) sealant. Use only the non-synthetic lubricant, P/N 1052271, in axles using RTV sealant (See 9.5 and 10.5 information below). American Axle and Manufacturing (A.A.M.) has approved the use of the new Fuel Efficient SAE 75W-90 synthetic axle lubricant for rear axles with the following restrictions: ^ All 8.6 inch axles are compatible as originally built. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage > Page 1238 ^ 9.5 inch axles on vehicles built prior to mid-February 1998 are NOT compatible because RTV sealant is used on the cover pans. On vehicles built after mid-February 1998 and equipped with 9.5 inch rear axles, synthetic lubricant, P/N 12378261, can be used because the RTV was replaced with a gasket. Other mid-February changes to the 9.5 inch rear axles include a new cover pan and cover pan fasteners common to other axles. Important: The new cover pan is not retrofittable to the housing of 9.5 inch axles on vehicles built prior to mid-February 1998. A new retrofit kit is available that will enable the use of synthetic lubricant for vehicles built after mid-February, 1998. ^ All 10.5 inch axles prior to March 3, 1999 are compatible if the axle shaft hub seal (RTV) is replaced with P/N 327739 gasket when changing to synthetic lubricant. As a product improvement, this new lubricant has been released into 1999 current production C/K vehicles built after the above VIN breakpoints (Except HD3SOO models which use 75W-140 synthetic lubricant, P/N 12346140). It is recommended that synthetic lubricant be used when changing rear axle lubricant for the following reasons: ^ Potential fuel economy ^ Lower operating temperature under severe usage conditions Important: ^ You do not need to wash/rinse any non-synthetic lubricant from the axle cavity when changing over to a synthetic lubricant. However, you should remove debris from the magnet and the bottom of the axle cavity whenever the axle fluid is changed. ^ On light-duty trucks equipped with locking differentials, do NOT use a limited-slip additive. Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage > Page 1239 Fluid - Differential: Technical Service Bulletins Drivetrain - Recommended Axle Lubricant File In Section: 0 - General Information Bulletin No.: 76-02-02A Date: October, 1998 INFORMATION Subject: Recommended Axle Lubricant Models: 1999 and Prior Rear Wheel Drive Passenger Cars, Light and Medium Duty Trucks, and Four Wheel Drive Vehicles This bulletin is being revised to add the 1998 and 1999 Model Years and add Vehicle Line and Recommended Axle Lubricant Information. Please discard Corporate Bulletin Number 76-02-02 (Section 0 - General Information). The following tables provide the latest information on recommended axle lubricant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage > Page 1240 Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Specifications > Capacity Specifications Fluid - Differential: Capacity Specifications Rear Axle Oil, Pts. ............................................................................................................................... ................................................................................ 4 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Specifications > Capacity Specifications > Page 1243 Fluid - Differential: Fluid Type Specifications Locking Differential (G80) This Article has been updated by TSB # 76-02-02A. SAE 80W-90 GL5 Gear Lubricant, GM P/N 1052271. Do not use limited slip additive. Non-Locking Differential Rear Axle with Non Limited Slip or Non Locking Differentials HD-3500 Trucks (Dana 11.0 axles) Recommended Lubricant - GM P/N 12346140, SAE 75W-140 Synthetic Gear Lubricant. 1999 GMT 800 Trucks Recommended Lubricant - GM P/N 12378261, SAE 75W-90 Synthetic Axle Lubricant. All other non limited-slip or non locking differentials including B and D cars, S/T, M/L, G, P, and C/K trucks except GMT 800 trucks, and as noted above. Recommended Lubricant - GM P/N 1052271 or an SAE 80W90 GL-5 Gear Lubricant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications Engine Oil: Technical Service Bulletins Engine - GM dexos 1 and dexos 2(R) Oil Specifications INFORMATION Bulletin No.: 11-00-90-001 Date: March 14, 2011 Subject: Global Information for GM dexos1(TM) and GM dexos2(TM) Engine Oil Specifications for Spark Ignited and Diesel Engines, Available Licensed Brands, and Service Fill for Adding or Complete Oil Change Models: 2012 and Prior GM Passenger Cars and Trucks Excluding All Vehicles Equipped with Duramax(TM) Diesel Engines GM dexos 1(TM) Information Center Website Refer to the following General Motors website for dexos 1(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 1(TM) Engine Oil Trademark and Icons The dexos(TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos‹›(TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos‹›(TM) specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 1(TM) engine oil. GM dexos 1(TM) Engine Oil Specification Important General Motors dexos 1(TM) engine oil specification replaces the previous General Motors specifications GM6094M, GM4718M and GM-LL-A-025 for most GM gasoline engines. The oil specified for use in GM passenger cars and trucks, PRIOR to the 2011 model year remains acceptable for those previous vehicles. However, dexos 1(TM) is backward compatible and can be used in those older vehicles. In North America, starting with the 2011 model year, GM introduced dexos 1(TM) certified engine oil as a factory fill and service fill for gasoline engines. The reasons for the new engine oil specification are as follows: - To meet environmental goals such as increasing fuel efficiency and reducing engine emissions. - To promote long engine life. - To minimize the number of engine oil changes in order to help meet the goal of lessening the industry's overall dependence on crude oil. dexos 1(TM) is a GM-developed engine oil specification that has been designed to provide the following benefits: - Further improve fuel economy, to meet future corporate average fuel economy (CAFE) requirements and fuel economy retention by allowing the oil to maintain its fuel economy benefits throughout the life of the oil. - More robust formulations for added engine protection and aeration performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 1248 - Support the GM Oil Life System, thereby minimizing the replacement of engine oil, before its life has been depleted. - Reduce the duplication of requirements for a large number of internal GM engine oil specifications. International Lubricants Standardization and Approval Committee (ILSAC) GF-5 Standard In addition to GM dexos 1(TM), a new International Lubricants Standardization and Approval Committee (ILSAC) standard called GF-5, was introduced in October 2010. - There will be a corresponding API category, called: SN Resource Conserving. The current GF-4 standard was put in place in 2004 and will become obsolete in October 2011. Similar to dexos 1(TM), the GF-5 standard will use a new fuel economy test, Sequence VID, which demands a statistically significant increase in fuel economy versus the Sequence VIB test that was used for GF-4. - It is expected that all dexos 1(TM) approved oils will be capable of meeting the GF-5 standard. However, not all GF-5 engine oils will be capable of meeting the dexos 1(TM) specification. - Like dexos(TM), the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers during October 2010, to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils. Corporate Average Fuel Economy (CAFE) Requirements Effect on Fuel Economy Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50 percent. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. New technology being introduced in GM vehicles designed to increase vehicle efficiency and fuel economy include direct injection, cam phasing, turbocharging and active fuel management (AFM). The demands of these new technologies on engine oil also are taken into consideration when determining new oil specifications. AFM for example can help to achieve improved fuel economy. However alternately deactivating and activating the cylinders by not allowing the intake and exhaust valves to open contributes to additional stress on the engine oil. Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. dexos 1(TM) will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. Using the right viscosity grade oil is critical for proper engine performance. Always refer to the Maintenance section of a vehicle Owner Manual for the proper viscosity grade for the engine being serviced. GM Oil Life System in Conjunction With dexos (TM) Supports Extended Oil Change Intervals To help conserve oil while maintaining engine protection, many GM vehicles are equipped with the GM Oil Life System. This system can provide oil change intervals that exceed the traditional 3,000 mile (4,830 km) recommendation. The dexos (TM) specification, with its requirements for improved oil robustness, compliments the GM Oil Life System by supporting extended oil change intervals over the lifetime of a vehicle. If all GM customers with GM Oil Life System equipped vehicles would use the system as intended, GM estimates that more than 100 million gallons of oil could be saved annually. GM dexos 2(TM) Information Center Website Refer to the following General Motors website for dexos 2(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 2(TM) Engine Oil Trademark and Icons Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 1249 The dexos (TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos (TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos (TM)specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 2(TM) engine oil. GM dexos 2(TM) Engine Oil Specification - dexos 2(TM) is approved and recommended by GM for use in Europe starting in model year 2010 vehicles, regardless of where the vehicle was manufactured. - dexos 2(TM) is the recommended service fill oil for European gasoline engines. Important The Duramax(TM) diesel engine is the exception and requires lubricants meeting specification CJ-4. - dexos 2(TM) is the recommended service fill oil for European light-duty diesel engines and replaces GM-LL-B-025 and GM-LL-A-025. - dexos 2(TM) protects diesel engines from harmful soot deposits and is designed with limits on certain chemical components to prolong catalyst life and protect expensive emission reduction systems. It is a robust oil, resisting degradation between oil changes and maintaining optimum performance longer. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Specifications > Capacity Specifications Engine Oil: Capacity Specifications TYPE.................................................................................................................................................... .......................................................................SG, SH Note: 1992-93 Syclone, and Typhoon engine oil must be Mobile 1 synthetic or equivalent CAPACITY, Refill: 4-cyl. 2.5L............................................................................................................... ..............................................................................2.8 Liters 3.0 Quarts Others................................... .............................................................................................................................................................. ...3.8 Liters 4.0 Quarts Capacity shown is without filter. When replacing filter, additional oil may be needed 1987-88 4.3L: Above 40°F (4°C).......................................................................................................... .....................................................................................................30‡ Above 0°F to (-18°C)................ .............................................................................................................................................................. ...................10W-30* Below 60°F (16°C).............................................................................................. ..........................................................................................................5W-30 1987-88 others, 1988-94 except Syclone & Typhoon: Above 40°F (4°C)............................................ .............................................................................................................................................................. .....30‡ Above 0°F to (-18°C)................................................................................................................ ...................................................................................10W-30 All temperatures................................... .............................................................................................................................................................. ..........5W-30* 1992-93 Syclone, Typhoon: All temperatures...................................................................................... .....................................................................................................................10W-30 *Preferred, except V6 4.3L ‡May be used when other recommended viscosities are unavailable Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold Power Steering Fluid: All Technical Service Bulletins P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1260 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1261 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1262 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold Power Steering Fluid: Customer Interest P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1268 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1269 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1270 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON > Page 1276 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON > Page 1282 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 08-01-38-001 > Jan > 08 > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant > Page 1296 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment > Page 1301 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1306 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1307 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1308 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1309 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1310 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1311 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1312 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1313 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1314 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1315 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1316 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1317 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1318 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1319 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1320 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1321 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1322 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1323 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1324 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1325 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1326 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1327 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations > Page 1332 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling Refrigerant: Technical Service Bulletins Contaminated R12 Refrigerant - Testing & Handling FILE IN SECTION: 1 - HVAC BULLETIN NO.: 53-12-05 DATE: May, 1995 SUBJECT: Contaminated R12 Refrigerant Testing and Handling MODELS: 1994 and Prior Passenger Cars and Trucks with R12 A/C Systems The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to perform normal A/C service procedures. Proper use of this tool can: ^ Prevent damage to your R12 recovery/recycling equipment. ^ Prevent contamination of previously recovered R12 in the recovery tank. ^ Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system. ^ Prevent the spread of contaminated R12 to other vehicles you service. If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for contamination prior to use. Sources of Contaminated R12 Refrigerant Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as other sources: ^ The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling. ^ Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers". ^ Poor quality or contaminated new or reprocessed R12 refrigerant. R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a refrigerant mixture which cannot be used in an A/C system. R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment to service each substitute refrigerant used. However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC (another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12 refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination of the R12 supply and the loss of the R12 recycling program. What To Do When Contamination is Detected Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant. Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 1337 contact or return to the previous repair facility. Explain that environmental regulations prohibit repair facilities from discharging ozone depleting A/C refrigerants into the atmosphere. Explain that recovery of this unknown refrigerant could damage your service equipment. If the customer wishes to pursue repairs through your facility, it is recommended that the proper A/C service equipment be purchased. General Motors recommends the Kent-Moore J 41428 "Scavenger", an air operated refrigerant recovery station, be used to remove unknown refrigerants. The air operated feature reduces the hazard of recovering potentially flammable refrigerants. Dealers should evaluate the need to purchase the equipment based on the number of contaminated vehicles they encounter. As an alternative to the initial purchase of a recovery only station, dealers should check locally for A/C specialty shops which may have the equipment to service substitute or contaminated refrigerants. They may be able to provide contaminated refrigerant recovery service to the dealer. The GM Service Technology Group has tested a recovery procedure where a 15 or 30 pound DOT approved refillable tank is fully evacuated then connected to a vehicle A/C system to recover the charge. Testing has shown that even when the recovery tank is cooled down in dry ice, the procedure does not guarantee the entire charge will be recovered. Since EPA regulations require full recovery of ozone depleting substances, GM does not recommend this procedure. Contaminated Refrigerant Disposal Although A/C refrigerant testing and disposal have not been a service practice in the mobile A/C industry, It has been common in the stationary A/C service industry for many years. Listed at the end of this bulletin are companies that provide refrigerant disposal service for the stationary A/C industry. Please be advised that GM has not independently evaluated these companies and is not in any way endorsing or promoting the use of these companies. Each of these companies has expressed an interest in providing refrigerant disposal service to GM dealers. In working with the stationary A/C industry, these companies typically receive large volumes of different refrigerants that have been mixed together. Unfortunately, because the volume of material returned by the mobile A/C industry will be in much smaller quantities, the cost of handling will be greater. To arrange for return of the refrigerant, simply call the company nearest you using the phone number listed below. The company will advise you on billing and shipping procedures. Disposal cost will vary between $3.00 and $5.00 per pound plus freight and handling. Shipping charges will vary by distance and location. In general, a 7 to 10 day turn-around time on the tank can be expected. The tank can be shipped via common carrier. Documents that your refrigerant has been properly disposed of will be sent to you with the return of your tank. As an alternative, many dealerships already have contracts in place with a disposal company who manages their hazardous wastes. In these cases, the disposal service may agree to handle containers of mixed refrigerants. Initially, the local disposal companies may be surprised by this inquiry. They may want to evaluate how much material will be collected before deciding whether to provide this service. As we move forward with the practice of testing R12 refrigerant, it will take time for all the questions to be answered. STG will provide additional information as soon as it is available. Understanding The PureGuard The PureGuard is a highly sensitive instrument capable of detecting R12 with 3% or less cross-contamination with other refrigerants. Any refrigerant mixture in excess of this amount poses a threat to both your refrigerant supply and recovery equipment. The PureGuard uses a pass/fail approach when monitoring the refrigerant and is precisely calibrated to cut power to the recovery machine if it encounters R12 mixed with any substitute refrigerants. The PureGuard ignores the presence of the air, dyes or oils in the refrigerant sampled. At least 20 psi must be present in the vehicle's A/C system for the PureGuard to function. Otherwise, refrigerant cannot be introduced to the PureGuard's test chamber. If a vehicle's A/C system contains less than 20 psi, it is an indication that the vehicle's system is nearly depleted of refrigerant. Occasionally, erratic PureGuard operation or service code 002 display will be encountered when A/C system pressure is exactly 20 psi. If this occurs, simply cycle the on/off switch to reset the PureGuard. After the 30 second PureGuard warm-up cycle, proceed immediately with vehicle recovery operation. Feedback from the field has indicated PureGuard service code 002 will also be displayed if the oil drain port is not sealed. Make sure the "0" ring seal in the cap is in place and that the cap is tight. If the PureGuard fails to clear or if you experience any other problems operating the PureGuard, contact Kent-Moore Technical Service at 1-800-345-2233. The unit should not be returned without first contacting Kent-Moore to obtain return authorization. Refrigerant Disposal Locations: United States Refrigerant Reclamation Inc. 12420 North Green River Rd. Evansville, IN 47711 800-207-5931, FAX - 812-867-1463 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 1338 Omega Refrigerant Reclamation 5263 North Fourth St. Irwindale, CA 91706 310-698-0991, FAX 310-696-1908 Refrigerant Management Svcs of Georgia 216 F. Atlanta Hwy. Cumming, GA 30130 Ph/FAX 800-347-5872 Refrigerant Reclaim Inc. 122 Old Stage Coach Rd. Dumfries, VA 22026 800-238-5902, FAX 703-441-0393 Gartech Refrigerant Reclamation Ctr. 2002 Platinum Garland, TX 75042 214-272-4070, FAX 214-272-8548 National Refrigerants, Inc. 11401 Roosevelt Blvd. Philadelphia, PA 19154 215-698-6620, FAX 215-602-8205 CFC Reclamation 1321 Swift North Kansas City, MO 64116 816-471-2511 Full Cycle-Global 550 James Street Lakewood, NJ 08701 908-370-3400, FAX - 908-370-3088 Refrigerant Reclaim Svcs, Inc. dba Full Cycle-Global 121 S. Norwood Drive Ft. Worth, TX 76053-7807 817-282-0022, FAX - 800-831-6182 Full Cycle-Global 2055 Silber, Ste. 109 Houston, TX 77055 713-681-7370, FAX - 713-681-9947 Full Cycle-Global 343 South Airline Hwy. Gonzales, LA 70737 504-644-5303, FAX - 504-644-1809 Full Cycle-Global 2966 Wireton Blue Island, IL 60406 708-388-8551, FAX - 708-388-8550 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye Refrigerant: Technical Service Bulletins A/C - R134a Leak Detection With Tracer Dye File In Section: 1 - HVAC Bulletin No.: 43-12-15 Date: November, 1994 Subject: R134a Leak Detection with Tracer Dye Models: All 1993-95 Vehicles with OEM R134a Systems All R12 Vehicles Retrofitted to R134a Systems R134a refrigerant is uniquely different from R12 refrigerant and requires some changes in the repair methods, tools and materials used in A/C service. Two important differences between R134a and R12 which affect the technicians ability to locate refrigerant leaks are: 1. The R134a molecule is smaller than the R12 molecule and therefore will leak through smaller openings. For the same size opening the smaller R134a molecule will leak out faster than the R12. 2. R134a refrigerant does not contain chlorine which the older R12 electronic leak detectors found very easy to identify. Many of today's electronic leak detectors have difficulty locating small R134a refrigerant leaks. In order to insure the highest quality in A/C system service, the J 39400 electronic leak detector was released as an essential tool for all GM dealers. This is the only refrigerant leak detector approved by GM for service on R134a vehicles. If maintained properly (Reference Bulletin No. 431218) and used in accordance with Service Manual procedures, the J 39400 will provide the most accurate and efficient method of locating R134a refrigerant leaks under most conditions. If the technician cannot find the leak with the J 39400 and the system is known to have lost charge, a new fluorescent leak tracer dye Kent-Moore* P/N J 41447, has been released that mixes with the R134a PAG oil. This dye is detectable through the use of an ultraviolet (black) light and glows yellow/green at the leak location (similar to using dye in engine leak detection). J 41447 IS THE ONLY APPROVED DYE BY GENERAL MOTORS. Not all R134a dyes are compatible with GM's PAG oil. Some dyes decrease the oil viscosity or chemically react with the oil. Use of alternate products may affect system reliability and cause premature compressor failure. Note: THIS DYE IS NOT TO BE USED IN R-12 SYSTEMS. Unlike mineral oil, the R134a PAG oil has special properties the technician should keep in mind. 1. PAG oil is water soluble and traces of PAG oil found at leaking joints are subject to "washing out". Condensation on refrigerant lines or the evaporator core may wash the PAG oil and leak dye off the line or off the core and out the condensate drain. This can make some leaks harder to find using the dye detector. Fluorescence at the drain opening would indicate a core leak. 2. Use of the R134a tracer dye requires time. Depending upon the leak rate, it may take between 15 minutes and 7 days for the leak to become visible. 3. The dye, mixed with the PAG oil, is retained in the system and is detectable for 2+ years. Do not double or triple charge the system with dye as this may cause reliability concerns. Use only the 1/4 oz. charge. The dye has a refrigerant leak detection notice sticker included with the package. Complete the sticker information and place near the charge label. Dye Injection R-134a dye can be injected two ways: 1. With the A/C system charged, use the instructions provided with the new R134a leak dye injection tool, J 41436. 2. With A/C system discharged, add dye into the newly replaced component assembly. It is important to note that it is normal to find oil traces at the compressor shaft seal during compressor operation, some oil will hydraulically seep past the shaft seal. This does not mean that the shaft seal is defective or that the refrigerant has leaked. Refrigerant leaks at the shaft seal should be verified with the electronic leak detector (J 39400) following the procedure detailed in the Service Manual. If, however, the amount of oil is excessive, the shaft seal is suspect and should be replaced. (For example, refrigerant oil has coated the clutch plate edge at gap between clutch and pulley, or oil slinging has occurred-oil line shows on underside of hood, etc.). Also, after working on A/C components with dye, it is important to wipe the joint and/or access ports clean of any residual dye with GM solvent (GM Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye > Page 1343 P/N 1050436) to prevent false diagnosis at a later point. * We believe this source and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Parts Information GM solvent, P/N 1050436, is currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431223 > Sep > 94 > A/C Refrigerant - Contamination Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 431223 > Sep > 94 > A/C Refrigerant - Contamination > Page 1348 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A > Page 1353 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > 922501A > Aug > 92 > A/C - Use of Alternate Refrigerants In CFC 12 Refrigerant: Technical Service Bulletins A/C - Use of Alternate Refrigerants In CFC 12 Number: 92-250-1A Section: 0A Date: AUGUST 1992 Corporate Bulletin No.: 231205 ASE No.: A7 Subject: USE OF ALTERNATE REFRIGERANTS IN CFC 12 REFRIGERANT MOBILE AIR CONDITIONERS Model and Year: GALL MODEL YEARS - ALL PASSENGER CARS AND TRUCKS INCLUDING GEO A number of inquiries have been received concerning the use of "alternate refrigerants" as a replacement for R-12 refrigerant in General Motors air conditioning systems. Regardless of any advertised claims, there are currently no substitutes for refrigerant R-12 approved by General Motors. At the present time, only new or recycled R-12 is approved for use in General Motors R-12 air conditioning systems. Based on studies performed to date, the use of "alternate refrigerants" in General Motors R-12 air conditioning systems may result in higher system pressures, higher leak rates or incompatibility with drying and sealing materials. System performance and reliability may also be affected. Service equipment manufacturers have indicated that cross-contaminating R-12 recovery/recycling equipment with "alternate refrigerants" may damage the equipment. General Motors supports the Society of Automotive Engineers recommended service procedures for recovery and recycling of R-12. The use of known "alternate refrigerants" without proper service practices for identifying vehicle systems containing these "alternate refrigerants" and dedicated recovery equipment to service those vehicles will contaminate the recycled supply of R-12 refrigerant. Contamination of the recycled R-12 refrigerant makes the refrigerant unusable for recharging air conditioning systems and could jeopardize the recycling program. At the present time, General Motors has not approved any "alternate refrigerant" for R-12 in R-12 air conditioning systems. Therefore, R-12 systems should continue to be serviced with new or recycled R-12 only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > Page 1358 Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins: > Page 1359 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 08-01-38-001 > Jan > 08 > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant > Page 1373 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment > Page 1378 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1383 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1384 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1385 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1386 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1387 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1388 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1389 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1390 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1391 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1392 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1393 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1394 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1395 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1396 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1397 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1398 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1399 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1400 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1401 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1402 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1403 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1404 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations > Page 1409 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling Refrigerant: Technical Service Bulletins Contaminated R12 Refrigerant - Testing & Handling FILE IN SECTION: 1 - HVAC BULLETIN NO.: 53-12-05 DATE: May, 1995 SUBJECT: Contaminated R12 Refrigerant Testing and Handling MODELS: 1994 and Prior Passenger Cars and Trucks with R12 A/C Systems The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to perform normal A/C service procedures. Proper use of this tool can: ^ Prevent damage to your R12 recovery/recycling equipment. ^ Prevent contamination of previously recovered R12 in the recovery tank. ^ Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system. ^ Prevent the spread of contaminated R12 to other vehicles you service. If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for contamination prior to use. Sources of Contaminated R12 Refrigerant Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as other sources: ^ The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling. ^ Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers". ^ Poor quality or contaminated new or reprocessed R12 refrigerant. R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a refrigerant mixture which cannot be used in an A/C system. R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment to service each substitute refrigerant used. However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC (another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12 refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination of the R12 supply and the loss of the R12 recycling program. What To Do When Contamination is Detected Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant. Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 1414 contact or return to the previous repair facility. Explain that environmental regulations prohibit repair facilities from discharging ozone depleting A/C refrigerants into the atmosphere. Explain that recovery of this unknown refrigerant could damage your service equipment. If the customer wishes to pursue repairs through your facility, it is recommended that the proper A/C service equipment be purchased. General Motors recommends the Kent-Moore J 41428 "Scavenger", an air operated refrigerant recovery station, be used to remove unknown refrigerants. The air operated feature reduces the hazard of recovering potentially flammable refrigerants. Dealers should evaluate the need to purchase the equipment based on the number of contaminated vehicles they encounter. As an alternative to the initial purchase of a recovery only station, dealers should check locally for A/C specialty shops which may have the equipment to service substitute or contaminated refrigerants. They may be able to provide contaminated refrigerant recovery service to the dealer. The GM Service Technology Group has tested a recovery procedure where a 15 or 30 pound DOT approved refillable tank is fully evacuated then connected to a vehicle A/C system to recover the charge. Testing has shown that even when the recovery tank is cooled down in dry ice, the procedure does not guarantee the entire charge will be recovered. Since EPA regulations require full recovery of ozone depleting substances, GM does not recommend this procedure. Contaminated Refrigerant Disposal Although A/C refrigerant testing and disposal have not been a service practice in the mobile A/C industry, It has been common in the stationary A/C service industry for many years. Listed at the end of this bulletin are companies that provide refrigerant disposal service for the stationary A/C industry. Please be advised that GM has not independently evaluated these companies and is not in any way endorsing or promoting the use of these companies. Each of these companies has expressed an interest in providing refrigerant disposal service to GM dealers. In working with the stationary A/C industry, these companies typically receive large volumes of different refrigerants that have been mixed together. Unfortunately, because the volume of material returned by the mobile A/C industry will be in much smaller quantities, the cost of handling will be greater. To arrange for return of the refrigerant, simply call the company nearest you using the phone number listed below. The company will advise you on billing and shipping procedures. Disposal cost will vary between $3.00 and $5.00 per pound plus freight and handling. Shipping charges will vary by distance and location. In general, a 7 to 10 day turn-around time on the tank can be expected. The tank can be shipped via common carrier. Documents that your refrigerant has been properly disposed of will be sent to you with the return of your tank. As an alternative, many dealerships already have contracts in place with a disposal company who manages their hazardous wastes. In these cases, the disposal service may agree to handle containers of mixed refrigerants. Initially, the local disposal companies may be surprised by this inquiry. They may want to evaluate how much material will be collected before deciding whether to provide this service. As we move forward with the practice of testing R12 refrigerant, it will take time for all the questions to be answered. STG will provide additional information as soon as it is available. Understanding The PureGuard The PureGuard is a highly sensitive instrument capable of detecting R12 with 3% or less cross-contamination with other refrigerants. Any refrigerant mixture in excess of this amount poses a threat to both your refrigerant supply and recovery equipment. The PureGuard uses a pass/fail approach when monitoring the refrigerant and is precisely calibrated to cut power to the recovery machine if it encounters R12 mixed with any substitute refrigerants. The PureGuard ignores the presence of the air, dyes or oils in the refrigerant sampled. At least 20 psi must be present in the vehicle's A/C system for the PureGuard to function. Otherwise, refrigerant cannot be introduced to the PureGuard's test chamber. If a vehicle's A/C system contains less than 20 psi, it is an indication that the vehicle's system is nearly depleted of refrigerant. Occasionally, erratic PureGuard operation or service code 002 display will be encountered when A/C system pressure is exactly 20 psi. If this occurs, simply cycle the on/off switch to reset the PureGuard. After the 30 second PureGuard warm-up cycle, proceed immediately with vehicle recovery operation. Feedback from the field has indicated PureGuard service code 002 will also be displayed if the oil drain port is not sealed. Make sure the "0" ring seal in the cap is in place and that the cap is tight. If the PureGuard fails to clear or if you experience any other problems operating the PureGuard, contact Kent-Moore Technical Service at 1-800-345-2233. The unit should not be returned without first contacting Kent-Moore to obtain return authorization. Refrigerant Disposal Locations: United States Refrigerant Reclamation Inc. 12420 North Green River Rd. Evansville, IN 47711 800-207-5931, FAX - 812-867-1463 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 1415 Omega Refrigerant Reclamation 5263 North Fourth St. Irwindale, CA 91706 310-698-0991, FAX 310-696-1908 Refrigerant Management Svcs of Georgia 216 F. Atlanta Hwy. Cumming, GA 30130 Ph/FAX 800-347-5872 Refrigerant Reclaim Inc. 122 Old Stage Coach Rd. Dumfries, VA 22026 800-238-5902, FAX 703-441-0393 Gartech Refrigerant Reclamation Ctr. 2002 Platinum Garland, TX 75042 214-272-4070, FAX 214-272-8548 National Refrigerants, Inc. 11401 Roosevelt Blvd. Philadelphia, PA 19154 215-698-6620, FAX 215-602-8205 CFC Reclamation 1321 Swift North Kansas City, MO 64116 816-471-2511 Full Cycle-Global 550 James Street Lakewood, NJ 08701 908-370-3400, FAX - 908-370-3088 Refrigerant Reclaim Svcs, Inc. dba Full Cycle-Global 121 S. Norwood Drive Ft. Worth, TX 76053-7807 817-282-0022, FAX - 800-831-6182 Full Cycle-Global 2055 Silber, Ste. 109 Houston, TX 77055 713-681-7370, FAX - 713-681-9947 Full Cycle-Global 343 South Airline Hwy. Gonzales, LA 70737 504-644-5303, FAX - 504-644-1809 Full Cycle-Global 2966 Wireton Blue Island, IL 60406 708-388-8551, FAX - 708-388-8550 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye Refrigerant: Technical Service Bulletins A/C - R134a Leak Detection With Tracer Dye File In Section: 1 - HVAC Bulletin No.: 43-12-15 Date: November, 1994 Subject: R134a Leak Detection with Tracer Dye Models: All 1993-95 Vehicles with OEM R134a Systems All R12 Vehicles Retrofitted to R134a Systems R134a refrigerant is uniquely different from R12 refrigerant and requires some changes in the repair methods, tools and materials used in A/C service. Two important differences between R134a and R12 which affect the technicians ability to locate refrigerant leaks are: 1. The R134a molecule is smaller than the R12 molecule and therefore will leak through smaller openings. For the same size opening the smaller R134a molecule will leak out faster than the R12. 2. R134a refrigerant does not contain chlorine which the older R12 electronic leak detectors found very easy to identify. Many of today's electronic leak detectors have difficulty locating small R134a refrigerant leaks. In order to insure the highest quality in A/C system service, the J 39400 electronic leak detector was released as an essential tool for all GM dealers. This is the only refrigerant leak detector approved by GM for service on R134a vehicles. If maintained properly (Reference Bulletin No. 431218) and used in accordance with Service Manual procedures, the J 39400 will provide the most accurate and efficient method of locating R134a refrigerant leaks under most conditions. If the technician cannot find the leak with the J 39400 and the system is known to have lost charge, a new fluorescent leak tracer dye Kent-Moore* P/N J 41447, has been released that mixes with the R134a PAG oil. This dye is detectable through the use of an ultraviolet (black) light and glows yellow/green at the leak location (similar to using dye in engine leak detection). J 41447 IS THE ONLY APPROVED DYE BY GENERAL MOTORS. Not all R134a dyes are compatible with GM's PAG oil. Some dyes decrease the oil viscosity or chemically react with the oil. Use of alternate products may affect system reliability and cause premature compressor failure. Note: THIS DYE IS NOT TO BE USED IN R-12 SYSTEMS. Unlike mineral oil, the R134a PAG oil has special properties the technician should keep in mind. 1. PAG oil is water soluble and traces of PAG oil found at leaking joints are subject to "washing out". Condensation on refrigerant lines or the evaporator core may wash the PAG oil and leak dye off the line or off the core and out the condensate drain. This can make some leaks harder to find using the dye detector. Fluorescence at the drain opening would indicate a core leak. 2. Use of the R134a tracer dye requires time. Depending upon the leak rate, it may take between 15 minutes and 7 days for the leak to become visible. 3. The dye, mixed with the PAG oil, is retained in the system and is detectable for 2+ years. Do not double or triple charge the system with dye as this may cause reliability concerns. Use only the 1/4 oz. charge. The dye has a refrigerant leak detection notice sticker included with the package. Complete the sticker information and place near the charge label. Dye Injection R-134a dye can be injected two ways: 1. With the A/C system charged, use the instructions provided with the new R134a leak dye injection tool, J 41436. 2. With A/C system discharged, add dye into the newly replaced component assembly. It is important to note that it is normal to find oil traces at the compressor shaft seal during compressor operation, some oil will hydraulically seep past the shaft seal. This does not mean that the shaft seal is defective or that the refrigerant has leaked. Refrigerant leaks at the shaft seal should be verified with the electronic leak detector (J 39400) following the procedure detailed in the Service Manual. If, however, the amount of oil is excessive, the shaft seal is suspect and should be replaced. (For example, refrigerant oil has coated the clutch plate edge at gap between clutch and pulley, or oil slinging has occurred-oil line shows on underside of hood, etc.). Also, after working on A/C components with dye, it is important to wipe the joint and/or access ports clean of any residual dye with GM solvent (GM Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye > Page 1420 P/N 1050436) to prevent false diagnosis at a later point. * We believe this source and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Parts Information GM solvent, P/N 1050436, is currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431223 > Sep > 94 > A/C Refrigerant - Contamination Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 431223 > Sep > 94 > A/C Refrigerant - Contamination > Page 1425 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A > Page 1430 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > 09-06-03-004D > Dec > 10 > Technical Service Bulletins for Refrigerant: > 922501A > Aug > 92 > A/C - Use of Alternate Refrigerants In CFC 12 Refrigerant: Technical Service Bulletins A/C - Use of Alternate Refrigerants In CFC 12 Number: 92-250-1A Section: 0A Date: AUGUST 1992 Corporate Bulletin No.: 231205 ASE No.: A7 Subject: USE OF ALTERNATE REFRIGERANTS IN CFC 12 REFRIGERANT MOBILE AIR CONDITIONERS Model and Year: GALL MODEL YEARS - ALL PASSENGER CARS AND TRUCKS INCLUDING GEO A number of inquiries have been received concerning the use of "alternate refrigerants" as a replacement for R-12 refrigerant in General Motors air conditioning systems. Regardless of any advertised claims, there are currently no substitutes for refrigerant R-12 approved by General Motors. At the present time, only new or recycled R-12 is approved for use in General Motors R-12 air conditioning systems. Based on studies performed to date, the use of "alternate refrigerants" in General Motors R-12 air conditioning systems may result in higher system pressures, higher leak rates or incompatibility with drying and sealing materials. System performance and reliability may also be affected. Service equipment manufacturers have indicated that cross-contaminating R-12 recovery/recycling equipment with "alternate refrigerants" may damage the equipment. General Motors supports the Society of Automotive Engineers recommended service procedures for recovery and recycling of R-12. The use of known "alternate refrigerants" without proper service practices for identifying vehicle systems containing these "alternate refrigerants" and dedicated recovery equipment to service those vehicles will contaminate the recycled supply of R-12 refrigerant. Contamination of the recycled R-12 refrigerant makes the refrigerant unusable for recharging air conditioning systems and could jeopardize the recycling program. At the present time, General Motors has not approved any "alternate refrigerant" for R-12 in R-12 air conditioning systems. Therefore, R-12 systems should continue to be serviced with new or recycled R-12 only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > Page 1435 Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > Page 1436 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > Page 1437 Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > All Other Service Bulletins for Refrigerant: > Page 1438 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 1447 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 1448 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 1449 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 1455 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 1456 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Specifications > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 1457 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Technical Service Bulletins > A/C - New PAG Oil Refrigerant Oil: Technical Service Bulletins A/C - New PAG Oil Bulletin No.: 02-01-39-004B Date: November 16, 2005 INFORMATION Subject: New PAG Oil Released Models: 2006 and Prior GM Passenger Cars and Trucks (Including Saturn) 2003-2006 HUMMER H2 2006 HUMMER H3 2005-2006 Saab 9-7X Built With R-134a Refrigeration System All Air Conditioning Compressor Types (Excluding R4 and A6 Type Compressors) Supercede: This bulletin is being revised to change the PAG oil part number used for R4 and A6 compressors with R-134a refrigerant systems. Please discard Corporate Bulletin Number 02-01-39-004A (Section 01 - HVAC). All General Motors vehicles built with R-134a refrigerant systems shall now be serviced with GM Universal PAG Oil (excluding vehicles equipped with an R4 or A6 compressor). R4 and A6 compressors with R-134a refrigerant systems shall use PAG OIL, GM P/N 12356151 (A/C Delco part number 15-118) (in Canada, use P/N 10953486). Important: The PAG oil referenced in this bulletin is formulated with specific additive packages that meet General Motors specifications and use of another oil may void the A/C systems warranty. Use this new PAG oil when servicing the A/C system on the vehicles listed above. Oil packaged in an 8 oz tube should be installed using A/C Oil Injector, J 45037. Refer to the HVAC Section of Service Information for detailed information on Oil Balancing and Capacities. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Specifications > Capacity Specifications Refrigerant Oil: Capacity Specifications Front The Air Conditioning system requires 236 ml (8 fl. oz.) of Polyalkaline Glycol (PAG) refrigerant oil. New refrigerant oil must be added to the system when components are replaced, as follows: a. All Compressors (drain and measure the oil) ^ If less than 30 ml (1 fl. oz.) is drained add 60 ml (2 fl. oz.) to the new compressor. ^ If more than 30 ml (1 fl. oz.) is drained add same amount that was drained to the new compressor. b. Accumulator-Add 105 ml (3.5 fl. oz.) of new oil to the replacement accumulator to compensate for oil retained by original accumulator desiccant and bag assemblies. The accumulator should only be replaced if leaking due to a perforation, damaged O-ring seat, or damaged threads. c. Evaporator-Add 90 ml (3 fl. oz.) of new refrigerant oil. d. Condenser-Add 30 ml (1 fl. oz.) of new refrigerant oil. Rear The Air Conditioning system requires 298 ml (11 fl. oz.) of Polyalkaline Glycol (PAG) refrigerant oil. New refrigerant oil must be added to the system when components are replaced, as follows: a. All Compressors (drain and measure the oil) ^ If less than 30 ml (1 fl. oz.) is drained add 60 ml (2 fl. oz.) to the new compressor. ^ If more than 30 ml (1 fl. oz.) is drained add same amount that was drained to the new compressor. b. Accumulator-Add 105 ml (3.5 fl. oz.) of new oil to the replacement accumulator to compensate for oil retained by original accumulator desiccant and bag assemblies. The accumulator should only be replaced if leaking due to a perforation, damaged O-ring seat, or damaged threads. c. Evaporator-Add 90 ml (3 fl. oz.) of new refrigerant oil. d. Condenser-Add 30 ml (1 fl. oz.) of new refrigerant oil. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Specifications > Capacity Specifications > Page 1464 Refrigerant Oil: Fluid Type Specifications REFRIGERANT OIL TYPE ^ R-134a PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding With ABS System Fig. 59 EHCU/BPMV Module Bleeding MANUAL BLEEDING The Electro-Hydraulic Control Unit Brake Pressure Modulator Valve Module (EHCU/BPMV) should be bled after replacement or if air is trapped in the unit or system. If system bleeding is required, the module must be bled thoroughly before the wheel cylinders and calipers. There are two bleeders on top of the unit that appear to be normal bleeders (figure 221). These are modulator bleeders and must remain closed when the unit is not pressurized. The internal bleeders are on either side of EHCU/BPMV module. The valves are used to open the internal passages within the EHCU/BPMV module. Both bleed valves must be rotated 1/4 to 1/2 turn counterclockwise before beginning the bleed process. The valve on the lefthand side is used for the rear brakes and the valve on the righthand side is used for the front brakes. NOTE: The ignition switch must be in the Off position or false diagnostic trouble codes may be stored. SPECIAL TOOL REQUIRED (or equivalent) ^ J-39177, Combination valve pressure bleeding tool (three required). PROCEDURE 1. Install combination valve depressor tool J-39177 to LH high pressure accumulator bleed stem of EHCU/BPMV module. 2. Install combination valve depressor tool J-39177 to RH high pressure accumulator bleed stem of EHCU/BPMV module. 3. Install combination valve depressor tool J-39177 to rear combination valve. 4. Ensure master cylinder fluid level, fill if required. 5. Bleed EHCU/BPMV module as follows: a. Slowly depress brake pedal one time and hold. b. Open left modulator bleeder, until fluid flows clearly or pedal is depressed, the close left bleeder. c. Slowly release brake pedal. d. Wait 15 seconds, then repeat steps until all air is bled from EHCU/BPMV module. e. Close LH internal bleed valve. Torque bleed valve to 7 Nm (5 ft lbs). f. Repeat preceding bleed steps for righthand bleed procedure. g. Remove special tools. 6. Ensure master cylinder fluid level, fill if required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 1469 7. Bleed wheel cylinder and calipers. 8. Turn ignition key to On position, then perform 3 function test with TECH 1 scanner. 9. Check brake pedal feel and braking performance; repeat procedure if required. General Information The braking system can be bled manually or with pressure bleeding equipment. If bleeding manually, check fluid level frequently. Brake fluid should never be reused. Before driving the vehicle, check brake operation to ensure a firm pedal has been obtained. Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always seal and wipe off brake fluid containers to prevent spills. Manual Fig. 7 Caliper Bleeding Hose Installation 1. If vehicle is equipped with a vacuum or hydraulic booster, relieve system by applying brakes several times with engine off. 2. Fill master cylinder reservoir with DOT 3 brake fluid. Maintain full level during bleeding procedures. 3. If master cylinder is replaced or suspected to have air in the bore, bleed it before calipers. a. Disconnect forward brake pipe connection at master cylinder and allow brake fluid to flow from connector port, then reconnect pipe but do not tighten. b. Slowly apply brake pedal to allow air to bleed from loose fitting, then tighten fitting before releasing brake pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air has been purged from bore. d. After all air has been removed from forward pipe, repeat procedure for rear pipe. 4. If the vehicle is equipped with four wheel anti-lock brakes (4WAL), the Brake Pressure Modular Valve (BPMV) may need to be bled. If the BPMV has been replaced or is suspected of having air trapped inside, bleed system as outlined in "Anti-Lock Brakes chapter." 5. Bleed each wheel in the following sequence: a. Right rear. b. Left rear. c. Right front. d. Left front. 6. Attach a suitable hose to wheel caliper valve and immerse opposite end of hose into a suitable clean container partially filled with clean brake fluid , Fig. 7. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 1470 7. Slowly apply brake pedal one time and hold, loosen the bleeder valve to purge air from caliper, then tighten bleeder valve and release pedal. 8. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from caliper. 9. Repeat bleeding sequence at each wheel until system is bled. 10. Check brake pedal for "sponginess and brake warning lamp for an indication of unbalanced pressure. Repeat bleeding procedure to correct either of these conditions. Pressure Fig. 8 Plastic Reservoir Bleeder Adapter Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 1471 Fig. 9 Cast Iron Reservoir Bleeder Adapter Installation A diaphragm type pressure bleeder must be used. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. Also, adapters are needed depending on the type of master cylinder reservoir used on the vehicle: Brake Bleeder Adapter (Plastic Reservoir) tool No. J 29567, or equivalent, Fig.8. Brake Bleeder Adapter (Cast Iron Reservoir) tool No. J 23518-01, or equivalent, Fig. 9. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 1472 Fig. 10 Combination Valve Bleeding Tool Installation 1. Fill the pressure tank at least 2/3 full of brake fluid. Bleeder must be bled each time fluid is added. 2. Charge pressure bleeder to 20-25 psi. 3. Use tool No. J 39177, or equivalent, to depress and hold valve stem on combination valve, Fig. 10. 4. Install master cylinder adapter tool required for type of reservoir, then install bleeder hose to adapter 5. Bleed each wheel in the following sequence: a. Right rear. b. Left rear. c. Right front. d. Left front. 6. Open bleeder tank valve. 7. Attach a hose to caliper bleeder valve and immerse the opposite end of the hose into a suitable, clean, container, partially filled with clean brake fluid. 8. Open bleeder valve at least 3/4 turn and allow fluid to flow until no air is seen in fluid, then close valve. 9. Repeat procedure at each wheel. 10. Check brakes for "sponginess. Repeat bleeding procedure if necessary. 11. Remove pressure bleeder, adaptors, and tools, then fill reservoir to proper level. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 1473 Brake Bleeding: Service and Repair Master Cylinder Bleeding This procedure can be performed with master cylinder on or off vehicle. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. It is not necessary to bleed entire hydraulic system after replacing master cylinder, providing master cylinder has been bled and filled during installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 1478 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Restraint Systems/Air Bag Systems/Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 1479 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Specifications Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Specifications > Page 1484 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 1493 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 1503 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > Page 1509 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > In-Line Fuse Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > In-Line Fuse > Page 1512 Outside Rear View Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > In-Line Fuse > Page 1513 Steering Column Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > Page 1514 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics Fuse Block: Technical Service Bulletins Shift Interlock/Fuse Block - Revised Schematics File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-81-26 Date: January, 1997 SERVICE MANUAL UPDATE Subject: Section 8A - Electrical Diagnosis - Revised Schematics Models: 1994 Chevrolet and GMC M/L Models Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics > Page 1519 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics > Page 1520 This bulletin revises the schematics on Pages 8A-11-8 and 8A-138-2 in the 1994 M/L Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Fuse Panel Fuse Block: Locations Fuse Panel Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Fuse Panel > Page 1523 Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Fuse Panel > Page 1524 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Fuse Panel > Page 1525 Fuse Block: Locations Fuse Block View Fuse Block Details: Front View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Fuse Panel > Page 1526 Fuse Block Details: Rear View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1529 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1530 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1531 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1532 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1533 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1534 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1535 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1536 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1537 Fuse Block: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1538 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1539 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1540 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1541 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1542 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1543 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1544 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1545 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1546 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1547 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1548 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1549 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1550 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1551 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1552 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1553 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1554 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1555 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1556 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1557 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1558 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1559 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1560 Fuse Block: Connector Views C109, Engine To Fuse Block C110, Engine To Fuse Block In-Line Fuse Block Tap C283, Fuse Block Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1561 C293, Fuse Block Tap C258, Fuse Block Tap C257, Fuse Block Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1562 C269, Fuse Block Tap C109, Fuse Block To Engine C110, Fuse Block To Engine In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1563 Fuse Block: Electrical Diagrams Convenience Center Details (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1564 Convenience Center Details (Part 2 Of 2) Wiring Diagram Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1565 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1566 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1567 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1568 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1569 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1570 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1571 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1572 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Application and ID > Front View Fuse Block Details: Front View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Application and ID > Front View > Page 1575 Fuse Block Details: Rear View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fusible Link > Component Information > Locations Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Specifications Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Locations > Convenience Center Relay Box: Locations Convenience Center Fuse Block And Convenience Center Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Locations > Convenience Center > Page 1584 Crossbody Harness The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Locations > Convenience Center > Page 1585 Relay Box: Locations Relay Center The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Convenience Center Tap C283, Convenience Center Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 1588 C206, Convenience Center To I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 1589 C206, Convenience Center To I/P Cluster In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 1590 C206, I/P Cluster To Convenience Center In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 1591 C206, I/P To Convenience Center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Page 1592 Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 1599 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Malfunction Indicator Lamp > Component Information > Service and Repair Malfunction Indicator Lamp: Service and Repair The CHECK ENGINE LAMP will be illuminated when the ignition switch is placed in the "ON" position. When the engine is started, the lamp should turn "OFF". If the lamp remains "ON" for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Control Module. After diagnosis and repair, the ECM memory can be cleared of codes by removing the Control Module fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the "OFF" position. NOTE If battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. - It is a good idea to record preset radio stations before disconnecting the negative battery cable. This will allow the stations to be reset as to not inconvenience the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair Vehicle Lifting: Service and Repair Fig. 1 Tip-up Type Hoist Pad (front). Fig. 1 Tip-up Type Hoist Pad (front). Fig. 2 Tip-up Type Hoist Pad (rear). Fig. 2 Tip-up Type Hoist Pad (rear). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair > Page 1607 Fig. 3 Screw Type Hoist Pad (front). Fig. 3 Screw Type Hoist Pad (front). Fig. 4 Screw Type Hoist Pad (rear). Fig. 4 Screw Type Hoist Pad (rear). Fig. 5 Suspension Type Hoist (front). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair > Page 1608 Fig. 5 Suspension Type Hoist (front). Fig. 6 Suspension Type Hoist (rear). Fig. 6 Suspension Type Hoist (rear). Fig. 7 Floor Jack (front). Fig. 7 Floor Jack (front). Fig. 8 Floor Jack (rear). Fig. 8 Floor Jack (rear). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair > Page 1609 Fig. 9 Floor Jack (front frame). Fig. 9 Floor Jack (front frame). Fig. 10 Floor Jack (rear frame). Fig. 10 Floor Jack (rear frame). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires Tires: Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1614 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1615 Tires: Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1616 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1617 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1618 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1619 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1620 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1621 Tires: Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1622 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1623 Tires: Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1624 Tires: Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: Customer Interest Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1633 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1634 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1635 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: Customer Interest Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels > Page 1640 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1646 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1647 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1648 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels > Page 1653 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1658 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1659 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: All Technical Service Bulletins Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1664 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1665 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1666 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: All Technical Service Bulletins Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels > Page 1671 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 04-03-10-012B > Feb > 08 > Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-03-10-102 > Jun > 99 > Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 72-05-05 > Aug > 97 > Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1688 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1689 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1690 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1696 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1697 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1698 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels > Page 1703 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1708 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1709 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 04-03-10-012B > Feb > 08 > Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-03-10-102 > Jun > 99 > Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 72-05-05 > Aug > 97 > Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1726 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1727 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1728 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Adjustments Wheel Bearing: Adjustments Front Wheel Bearings 1. Raise and support front of vehicle. 2. While rotating wheel assembly in forward direction, tighten spindle nut to specifications to fully seat the bearings. 3. Back off spindle nut until just loose, then hand tighten spindle nut. 4. Loosen nut until hole in spindle aligns with a spindle nut slot, then install new cotter pin. 5. When properly adjusted, endplay should measure 0.001-0.005 inch. 6. Install rotor/hub cap, then lower vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front Wheel Bearing: Service and Repair Front Front Wheel Rotor/Hub Assembly 2WD Figure 5 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1734 Figure 6 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1735 Wheel Bearing: Service and Repair Rear Dana/Spicer Full Floating Axle REAR WHEEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Bearing & Cup REAR HUB AND/OR BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum REAR HUB AND/OR BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1736 5. Pull hub and drum straight off axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Hub > Component Information > Service and Repair Wheel Hub: Service and Repair Front Wheel Rotor/Hub Assembly 2WD Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Hub > Component Information > Service and Repair > Page 1740 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Customer Interest for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: Customer Interest Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Customer Interest for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 1749 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: All Technical Service Bulletins Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 1755 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Page 1756 Wheel Fastener: Specifications Wheel Nut Wheel Nut Wheel Lug Nuts 100 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Vehicle Lifting > Component Information > Service and Repair Vehicle Lifting: Service and Repair Fig. 1 Tip-up Type Hoist Pad (front). Fig. 1 Tip-up Type Hoist Pad (front). Fig. 2 Tip-up Type Hoist Pad (rear). Fig. 2 Tip-up Type Hoist Pad (rear). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Vehicle Lifting > Component Information > Service and Repair > Page 1760 Fig. 3 Screw Type Hoist Pad (front). Fig. 3 Screw Type Hoist Pad (front). Fig. 4 Screw Type Hoist Pad (rear). Fig. 4 Screw Type Hoist Pad (rear). Fig. 5 Suspension Type Hoist (front). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Vehicle Lifting > Component Information > Service and Repair > Page 1761 Fig. 5 Suspension Type Hoist (front). Fig. 6 Suspension Type Hoist (rear). Fig. 6 Suspension Type Hoist (rear). Fig. 7 Floor Jack (front). Fig. 7 Floor Jack (front). Fig. 8 Floor Jack (rear). Fig. 8 Floor Jack (rear). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Vehicle Lifting > Component Information > Service and Repair > Page 1762 Fig. 9 Floor Jack (front frame). Fig. 9 Floor Jack (front frame). Fig. 10 Floor Jack (rear frame). Fig. 10 Floor Jack (rear frame). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Camshaft, Engine > Component Information > Specifications > Valve Clearance Camshaft: Specifications Valve Clearance This engine uses hydraulic lifters. Valve stem to rocker arm clearance is zero. Refer to, Cylinder Head Assembly/ Valve, Intake/Exhaust/ Adjustments for lash adjustment procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Camshaft, Engine > Component Information > Specifications > Valve Clearance > Page 1773 Camshaft: Specifications Camshaft Engine Liter/CID [04] ........................................................................................................................... ............................................................ 4.3L/V6-262 All specifications given in inches. Camshaft Journal Diameter ................................................................................................................. ............................................................ 1.8682-1.8692 Camshaft Endplay .......................................... ................................................................................................................................................. 0.0040-0.0120 Camshaft Runout (Max.) ............................................................................................. .................................................................................................. 0.001 Lifter Diameter ........................ .............................................................................................................................................................. ......... 0.8420-0.8427 Lifter To Bore Clearance ................................................................................... ............................................................................................. 0.0008-0.0025 [04] VIN Z. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Camshaft, Engine > Component Information > Specifications > Page 1774 Camshaft: Service and Repair Fig. 13 Valve Timing Marks 1. Disconnect battery ground cable. 2. Remove engine cover and air cleaner, then drain cooling system. 3. Remove valve covers, rocker arms and pushrods. 4. Remove valve lifters. 5. Remove distributor. 6. Remove intake manifold. 7. Remove radiator, fan and pulley, then the water pump. 8. Remove torsional damper using a suitable tool, then the engine front cover. 9. Align timing marks, Fig. 13, then remove timing chain and camshaft gear. Tap sprocket on its lower edge, using a suitable mallet, to facilitate removal. 10. Remove camshaft sprocket, stud, and timing chain. 11. Install two or three 5/16 x 18 x 4 inch bolts into in camshaft bolt holes, then using these bolts as a handle, carefully pull camshaft from block. Use caution not to damage camshaft bearings. 12. Reverse procedure to install. When installing camshaft, align marks on camshaft and crankshaft sprockets, Fig. 13. Tighten to specifications. If a new camshaft is being installed, replace all valve lifters. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Lifter / Lash Adjuster, Valve > Component Information > Service and Repair Lifter / Lash Adjuster: Service and Repair Fig. 11 Cross-Sectional View Of Hydraulic Valve Lifter REPLACEMENT/INSTALLATION 1. Remove intake manifold. 2. Remove valve cover, rocker arm and pushrods on cylinder(s) to be serviced. 3. Remove retainer and restrictors, if equipped, then the valve lifter. 4. Place lifters in organizing rack after removal. Lifters must be installed in same from which they were removed. 5. Reverse procedure to install. Coat foot of valve lifters with Molykote or equivalent. Following installation, lubricate lifter roller and body with Engine Oil Supplement or equivalent. If new lifter(s) are installed, change engine oil and filter. 6. Adjust valves. DISASSEMBLE 1. Depress plunger with a pushrod, then remove pushrod seat retainer, Fig. 11, using a suitable screwdriver. 2. Remove pushrod seat, metering valve, plunger, ball check valve assembly and plunger spring. 3. Pry ball retainer loose from plunger and remove ball check valve and spring. CLEANING & INSPECTION 1. Clean all lifter components in suitable solvent. 2. Inspect all parts for wear or damage. If any one component is worn or damaged, the entire assembly must be replaced. 3. If lifter body wall is worn, inspect cylinder block lifter bore. 4. If bottom of lifter is worn, inspect camshaft lobe. 5. If pushrod seat is worn, inspect pushrod. 6. Check roller for flat spots, pits, and missing or broken needle bearings. If damaged, also check mating camshaft lobe. 7. Check roller for freedom of movement. ASSEMBLE 1. Position check ball on small hole in bottom of plunger, then install spring and ball retainer. 2. Install plunger spring over ball retainer, then slide lifter body over spring and plunger. Ensure oil holes in lifter body and plunger are aligned. 3. Turn the assembly has open end up. Fill assembly with SAE 10.0 oil, then depress plunger with a 1/8 inch drift pin. Insert a 1/16 inch drift pin through both oil holes to hold plunger down against spring tension. 4. Remove the 1/8 inch drift pin and refill assembly with SAE 10.0 oil, then install metering valve and pushrod seat. 5. Install pushrod seat retainer, then push down on pushrod seat and remove 1/16 inch drift pin from oil holes. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Push Rod > Component Information > Service and Repair Push Rod: Service and Repair 1. Disconnect battery ground cable. 2. Remove engine cover, then the air cleaner assembly. 3. To remove right side valve cover, proceed as follows: a. Remove heat stove tube. b. Remove diverter valve, bracket and hoses. c. Disconnect spark plug wire brackets, then the spark plug wires and clip. d. Disconnect dipstick tube bracket from cylinder head. e. Remove PCV valve, then move wire harness away from valve cover. f. Remove valve cover attaching bolts, then the valve cover and gasket. 4. To remove left side valve cover, proceed as follows: a. Remove air cleaner, oil filler tube, then the AIR pipe and check valve. b. Disconnect alternator rear brackets, then the crankcase ventilation pipe. c. Remove valve cover attaching bolts, then the valve cover and gasket. 5. Remove rocker arm attaching nuts, then the rocker arms with balls. 6. Remove pushrods. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm Nut Torque Rocker Arm Assembly: Specifications Rocker Arm Nut Torque VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm Nut Torque > Page 1785 Rocker Arm Assembly: Specifications Rocker Arm Stud Torque ROCKER ARM STUD TORQUE ^ Rocker Arm Stud to Cylinder Head ................................................................................................................................................ 47 Nm (35 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Specifications > Page 1786 Rocker Arm Assembly: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Rocker arm studs that have damaged threads or are loose in cylinder head should be replaced with oversize studs. Studs are available in oversizes of 0.003 and 0.013 inch and can be installed after reaming holes as follows: 1. Remove stud using stud remover tool No. J-5802-01, or equivalent, with a nut and flat washer placed over the tool. 2. Ream hole for oversize stud using reamer tool No. J-5715, or equivalent, for 0.003 inch oversize or tool No. J-6036, or equivalent, for 0.013 inch oversize. 3. Apply hypoid axle lubricant to press fit area of stud, then install new stud using stud installer tool No. J-6880, or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace > Page 1789 Rocker Arm Assembly: Service and Repair Rocker Arms Replace 1. Disconnect battery ground cable. 2. Remove engine cover, then the air cleaner assembly. 3. To remove right side valve cover, proceed as follows: a. Remove heat stove tube. b. Remove diverter valve, bracket and hoses. c. Disconnect spark plug wire brackets, then the spark plug wires and clip. d. Disconnect dipstick tube bracket from cylinder head. e. Remove PCV valve, then move wire harness away from valve cover. f. Remove valve cover attaching bolts, then the valve cover and gasket. 4. To remove left side valve cover, proceed as follows: a. Remove air cleaner, oil filler tube, then the AIR pipe and check valve. b. Disconnect alternator rear brackets, then the crankcase ventilation pipe. c. Remove valve cover attaching bolts, then the valve cover and gasket. 5. Remove rocker arm attaching nuts, then the rocker arms with balls. 6. Remove pushrods. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Balance Shaft > Component Information > Specifications Balance Shaft: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Journal Bearing Diameter Front .................................................................................................................................................... ...................................................... 2.1648-2.1654 Rear ...................................................................... ...................................................................................................................................... 1.4994-1.5000 Rear Bearing Journal Clearance ......................................................................................................... ........................................................ 0.0010-0.0036 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Connecting Rod Bearing > Component Information > Specifications Connecting Rod Bearing: Specifications Connecting rod bearings are available in standard size and 0.001 and 0.002 inch undersize for use with new and used standard size crankshafts and 0.010 and 0.020 inch undersize for use with reconditioned crankshafts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Connecting Rod, Engine > Component Information > Specifications Connecting Rod: Specifications Connecting Rod Cap 20 lb ft + 70 degrees Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Crankshaft Main Bearing: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1808 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1809 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1810 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1811 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1812 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1813 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1814 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Crankshaft Main Bearing: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1820 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1821 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1822 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1823 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1824 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1825 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1826 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Crankshaft Main Bearing: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: All Technical Service Bulletins Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Crankshaft Main Bearing: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues > Page 1832 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Crankshaft Main Bearing: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues > Page 1838 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Specifications > Bearing Undersize Availability Crankshaft Main Bearing: Specifications Bearing Undersize Availability Main bearings are available in standard size and undersizes of 0.001, 0.002, 0.009, 0.010 and 0.020 inch. Connecting rod bearings are available in standard size and 0.001 and 0.002 inch undersize for use with new and used standard size crankshafts and 0.010 and 0.020 inch undersize for use with reconditioned crankshafts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft, Engine > Component Information > Specifications > Main Bearing Torque Specifications Crankshaft: Specifications Main Bearing Cap Main Bearing Cap Torque Specification 75 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft, Engine > Component Information > Specifications > Main Bearing Torque Specifications > Page 1845 Crankshaft: Specifications Crankshaft Dimensions Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Crankshaft Journals Main Bearing Journal Diameter ........................................................................................................... ..................................................................... [6] Connecting Rod Journal Diameter .......................................................................................................................................................... 2.2487-2.2497 Maximum Out Of Round All ......................................................................................... ...................................................................................... 0.0010 Runout Service Limit ........................ .............................................................................................................................................................. .......... [02] Bearing Clearance Main Bearings ...................................................................................................................................... ...................................................................... [07] Connecting Rod Bearings ...................................... ................................................................................................................................................... [08] Thrust Bearing ..................................................................................................................................... ..................................................... 0.0020-0.0070 Connecting Rods Pin Clearance ...................................................................................................................................... ....................................................................... [03] Side Clearance ..................................................... ...................................................................................................................................... 0.0060-0.0140 [02] If main journals are misaligned, crankshaft is bent & must be replaced. [03] 0.0008-0.0016 inch interference fit. [06] Front No. 1 journal, 2.4484-2.4493 inches; Nos. 2, 3, & 4 journals, 2.4481-2.4490 inches; No. 5 journal, 2.4479-2.4488 inches. [07] Production: Front, .0008-.0020 inch; intermediate, .0011-.0023 inch; rear, .0017-.0032 inch. Service: Front, .0010-.0015 inch; intermediate, .0010-.0025 inch; rear, .0025-.0035 inch. [08] Production, .0013-.0035 inch; service, .0020-.0030 inch. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Harmonic Balancer Crankshaft Pulley > Component Information > Technical Service Bulletins > Crankshaft Balancer - Removal/Installation Tool Harmonic Balancer - Crankshaft Pulley: Technical Service Bulletins Crankshaft Balancer Removal/Installation Tool File In Section: 6 - Engine Bulletin No.: 57-61-38 Date: January, 1996 SERVICE MANUAL UPDATE Subject: Section 6A - Engine Mechanical - Crankshaft Balancer Remover/Installer Tool Incorrectly Referenced Models: 1990-96 Chevrolet and GMC Truck S/T; M/L, C/K, P, G Models 1991-94 Oldsmobile Bravada 1996 Oldsmobile Bravada The crankshaft balancer remover/installer tool J 39046 listed in some 1990-96 service information sections 6A2, 6A3, 6A4, 6A5, 6A6, 6A7, 6A2B, 6A3B, 6A4B, 6A5B, and 6A6B is incorrectly referenced. The correct tool number for the truck models listed above is J 23523-F or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Piston, Engine > Component Information > Specifications Piston: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Piston Diameter (Std.) [01] .................................................................................................................. ......................................................... 3.9988-4.0008 Piston Clearance ............................................... ..................................................................................................................................... 0.0007-0.0017 [07] Piston Pin Diameter (Std.) ............................................................................................................ .............................................................. 0.9270-0.09273 Pin To Piston Bore Clearance [05] ............. ............................................................................................................................................................. 0.0010 Piston Rings End Gap [02] Comp. .................................................................................................................................................. .................................................................. [21] Oil .............................................................................. ......................................................................................................................................... 0.015 Side Clearance Comp. .................................................................................................................................................. ................................................. 0.0014-0.0032 Oil .............................................................................. ........................................................................................................................... 0.0014-0.0032 [01] Measured at 90 deg. angle to piston pin. [02] Minimum. [05] Maximum. [07] Service limit, 0.0027 inch. [21] Top ring, 0.010 inch; second ring, 0.018 inch. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 1858 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Page 1859 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Page 1860 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm Nut Torque Rocker Arm Assembly: Specifications Rocker Arm Nut Torque VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm Nut Torque > Page 1868 Rocker Arm Assembly: Specifications Rocker Arm Stud Torque ROCKER ARM STUD TORQUE ^ Rocker Arm Stud to Cylinder Head ................................................................................................................................................ 47 Nm (35 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Specifications > Page 1869 Rocker Arm Assembly: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Rocker arm studs that have damaged threads or are loose in cylinder head should be replaced with oversize studs. Studs are available in oversizes of 0.003 and 0.013 inch and can be installed after reaming holes as follows: 1. Remove stud using stud remover tool No. J-5802-01, or equivalent, with a nut and flat washer placed over the tool. 2. Ream hole for oversize stud using reamer tool No. J-5715, or equivalent, for 0.003 inch oversize or tool No. J-6036, or equivalent, for 0.013 inch oversize. 3. Apply hypoid axle lubricant to press fit area of stud, then install new stud using stud installer tool No. J-6880, or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace > Page 1872 Rocker Arm Assembly: Service and Repair Rocker Arms Replace 1. Disconnect battery ground cable. 2. Remove engine cover, then the air cleaner assembly. 3. To remove right side valve cover, proceed as follows: a. Remove heat stove tube. b. Remove diverter valve, bracket and hoses. c. Disconnect spark plug wire brackets, then the spark plug wires and clip. d. Disconnect dipstick tube bracket from cylinder head. e. Remove PCV valve, then move wire harness away from valve cover. f. Remove valve cover attaching bolts, then the valve cover and gasket. 4. To remove left side valve cover, proceed as follows: a. Remove air cleaner, oil filler tube, then the AIR pipe and check valve. b. Disconnect alternator rear brackets, then the crankcase ventilation pipe. c. Remove valve cover attaching bolts, then the valve cover and gasket. 5. Remove rocker arm attaching nuts, then the rocker arms with balls. 6. Remove pushrods. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Spring > Component Information > Specifications Valve Spring: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Free Length ......................................................................................................................................... ........................................................................... [04] Out Of Square Limit .......................................... ......................................................................................................................................................... 0.062 Installed Height .......................................................................................................................... ....................................................................... 1.687-1.750 Pressure, Lbs. @ Inches Closed Intake ................................................................................................................................................... ........................................... 76.0-84.0 @ 1.700 Exhaust ..................................................................... ...................................................................................................................... 76.0-84.0 @ 1.700 Open Intake ................................................................................................................................................... ............................................... 194-206 @ 1.25 Exhaust ..................................................................... .......................................................................................................................... 194-206 @ 1.25 [04] Outer spring, 2.030 inches; damper spring, 1.860 inches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve, Intake/Exhaust > Component Information > Specifications > Valve Specifications Valve: Specifications Valve Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Stem Diameter Std. Intake ................................................................................................................................................... ...................................................... 0.3410-0.3417 Exhaust ................................................................ ...................................................................................................................................... 0.3410-0.3417 Maximum Tip Refinish ......................................................................................................................... ........................................................................ [03] Face Angle .......................................................... ....................................................................................................................................................... 45 deg. Margin [01] Intake ................................................................................................................................................... .................................................................. 0.0315 Exhaust ................................................................. .................................................................................................................................................. 0.0315 Valve Lash ........................................................................................................................................... ........................................................................... [07] [01] Minimum. [03] Grind only enough to provide true surface. After grinding valve stems, ensure sufficient clearance remains between rocker arm & valve spring cap or rotator. [07] Torque rocker arm nut to 20 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve, Intake/Exhaust > Component Information > Specifications > Valve Specifications > Page 1880 Valve: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics Drive Belt: Technical Service Bulletins Engine - Drive Belt Misalignment Diagnostics INFORMATION Bulletin No.: 08-06-01-008A Date: July 27, 2009 Subject: Diagnosing Accessory Drive Belt / Serpentine Belt Noise and Availability and Use of Kent-Moore EN-49228 Laser Alignment Tool - Drive Belt Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add a model year and update the Tool Information. Please discard Corporate Bulletin Number 08-06-01-008 (Section 06 - Engine). Background Several aftermarket companies offer laser alignment tools for accessory drive systems that can be very helpful in eliminating drive belt noise as a result of misaligned pulleys. Typically pricing ranges from $160 - $200. EN-49228 Laser Alignment Tool - Drive Belt The GM Tool program has now made available a competitive, simple to use and time-saving laser tool to assist in achieving precise alignment of the drive belt pulleys. This optional tool removes the guesswork from proper pulley alignment and may serve to reduce comebacks from: - Drive Belt Noise - Accelerated Drive Belt Wear - Drive Belt Slippage Instructions The instructions below are specific only to the truck Gen IV V-8 family of engines. These instructions are only for illustrative purposes to show how the tool may be used. Universal instructions are included in the box with the Laser Alignment Tool - Drive Belt. Caution - Do not look directly into the beam projected from the laser. - Use caution when shining the laser on highly polished or reflective surfaces. Laser safety glasses help reduce laser beam glare in many circumstances. - Always use laser safety glasses when using the laser. Laser safety glasses are not designed to protect eyes from direct laser exposure. 1. Observe and mark the serpentine belt orientation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1886 2. Remove the serpentine belt from the accessory drive system. 3. Install the tool onto the power steering pulley. Position the legs of the tool into the outer grooves of the pulley, farthest from the front of the engine. 4. Install the retaining cord around the pulley and to the legs of the tool. 5. Put on the laser safety glasses provided with the tool. 6. Depress the switch on the rear of the tool to activate the light beam. 7. Rotate the power steering pulley as required to project the light beam onto the crankshaft balancer pulley grooves. 8. Inspect for proper power steering pulley alignment. - If the laser beam projects onto the second rib or raised area (1), the pulleys are aligned properly. - If the laser beam projects more than one-quarter rib 0.9 mm (0.035 in) mis-alignment, adjust the position of the power steering pulley as required. - Refer to SI for Power Steering Pulley Removal and Installation procedures. 9. Install the serpentine belt to the accessory drive system in the original orientation. 10. Operate the vehicle and verify that the belt noise concern is no longer present. Tool Information Please visit the GM service tool website for pricing information or to place your order for this tool. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1887 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1888 Drive Belt: Technical Service Bulletins Engine - Serpentine Drive Belt Wear Information Bulletin No.: 04-06-01-013 Date: April 29, 2004 INFORMATION Subject: Information on Serpentine Belt Wear Models: 2004 and Prior Passenger Cars and Trucks 2003-2004 and Prior HUMMER H2 All current GM vehicles designed and manufactured in North America were assembled with serpentine belts that are made with an EPDM material and should last the life of the vehicle. It is extremely rare to observe any cracks in EPDM belts and it is not expected that they will require maintenance before 10 years or 240,000 km (150,000 mi) of use. Older style belts, which were manufactured with a chloroprene compound, may exhibit cracks depending on age. However, the onset of cracking typically signals that the belt is only about halfway through its usable life. A good rule of thumb for chloroprene-based belts is that if cracks are observed 3 mm (1/8 in) apart, ALL AROUND THE BELT, the belt may be reaching the end of its serviceable life and should be considered a candidate for changing. Small cracks spaced at greater intervals should not be considered as indicative that the belt needs changing. Any belt that exhibits chunking should be replaced. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Page 1889 Drive Belt: Service and Repair Fig. 17 Serpentine Drive Belt Routing 1. Insert a 1/2 inch breaker bar into the tensioner pulley. 2. Rotate tensioner counterclockwise, then remove drive belt. 3. Route drive belt over all pulleys except water pump, Fig. 17. 4. Insert a 1/2 inch breaker bar into the tensioner pulley. 5. Rotate tensioner counterclockwise then slip belt over water pump pulley. 6. Ensure proper belt tracking around each pulley. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair Engine Mount: Service and Repair Fig. 1 Front Engine Mount Replacement FRONT Broken or deteriorated engine mountings can cause misalignment and eventual destruction of certain drive train components. When a single mounting breakage occurs, the remaining mountings are subjected to abnormally high stress. Inspection of these mountings for damage is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair > Page 1893 The front engine mounting brackets use hollow engine mount bolts to retain the engine mount bracket to the engine. The purpose of these bolts is to allow the engine assembly to break free of its mount in a very extreme frontal collision situation. When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or crankshaft pulley. Due to the small clearance between the oil pan and the pump screen, jacking against the oil pan may cause it to be bent against the pump screen, resulting in a damaged oil pickup unit. Do not use air tools to remove the hollow engine mount bracket bolts. This will snap the bolt heads off, requiring removal of the thread portion of the bolt from the engine block. Do not reuse hollow engine mount bolts. They are coated with Loctite and must be replaced when removed for any reason. 1. Remove mount retaining bolt from below frame mounting bracket. 2. Raise front of engine to remove weight from mount and to place slight tension on the rubber cushion, remove mount attaching bolts, then the mount. Check for interference between rear of engine and cowl panel. Raise engine only enough to provide sufficient clearance for mount removal. 3. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair > Page 1894 Fig. 3 Rear Engine Mount Replacement REAR Broken or deteriorated engine mountings can cause misaligned and eventual destruction of certain drive train components. When a single mounting breakage occurs, the remaining mountings are subjected to abnormally high stress. When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or crankshaft pulley. Due to the small clearance between the oil pan and the pump screen, jacking against the oil pan may cause it to be bent against the pump screen, resulting in a damaged oil pickup unit. Do not use air tools to remove the hollow engine mount bracket bolts. This will snap the bolt heads off, requiring removal of the thread portion of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair > Page 1895 the bolt from the engine block. Do not reuse hollow engine mount bolts. They are coated with Loctite and must be replaced when removed for any reason. 1. Support transmission to relieve weight from rear mounts, Fig. 3. 2. Remove crossmember to mount attaching nuts. 3. Remove mount attaching bolts, then raise transmission and remove mount. 4. Reverse procedure to install. Align mount to crossmember when lowering transmission into position. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil Pressure > Component Information > Specifications Engine Oil Pressure: Specifications Normal Oil Pressure, psi ........................................................................ Minimum pressures: 25-50 lbs. @ 1200 RPM; 42-60 lbs. @ 2400-5000 RPM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications Engine Oil: Technical Service Bulletins Engine - GM dexos 1 and dexos 2(R) Oil Specifications INFORMATION Bulletin No.: 11-00-90-001 Date: March 14, 2011 Subject: Global Information for GM dexos1(TM) and GM dexos2(TM) Engine Oil Specifications for Spark Ignited and Diesel Engines, Available Licensed Brands, and Service Fill for Adding or Complete Oil Change Models: 2012 and Prior GM Passenger Cars and Trucks Excluding All Vehicles Equipped with Duramax(TM) Diesel Engines GM dexos 1(TM) Information Center Website Refer to the following General Motors website for dexos 1(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 1(TM) Engine Oil Trademark and Icons The dexos(TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos‹›(TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos‹›(TM) specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 1(TM) engine oil. GM dexos 1(TM) Engine Oil Specification Important General Motors dexos 1(TM) engine oil specification replaces the previous General Motors specifications GM6094M, GM4718M and GM-LL-A-025 for most GM gasoline engines. The oil specified for use in GM passenger cars and trucks, PRIOR to the 2011 model year remains acceptable for those previous vehicles. However, dexos 1(TM) is backward compatible and can be used in those older vehicles. In North America, starting with the 2011 model year, GM introduced dexos 1(TM) certified engine oil as a factory fill and service fill for gasoline engines. The reasons for the new engine oil specification are as follows: - To meet environmental goals such as increasing fuel efficiency and reducing engine emissions. - To promote long engine life. - To minimize the number of engine oil changes in order to help meet the goal of lessening the industry's overall dependence on crude oil. dexos 1(TM) is a GM-developed engine oil specification that has been designed to provide the following benefits: - Further improve fuel economy, to meet future corporate average fuel economy (CAFE) requirements and fuel economy retention by allowing the oil to maintain its fuel economy benefits throughout the life of the oil. - More robust formulations for added engine protection and aeration performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 1904 - Support the GM Oil Life System, thereby minimizing the replacement of engine oil, before its life has been depleted. - Reduce the duplication of requirements for a large number of internal GM engine oil specifications. International Lubricants Standardization and Approval Committee (ILSAC) GF-5 Standard In addition to GM dexos 1(TM), a new International Lubricants Standardization and Approval Committee (ILSAC) standard called GF-5, was introduced in October 2010. - There will be a corresponding API category, called: SN Resource Conserving. The current GF-4 standard was put in place in 2004 and will become obsolete in October 2011. Similar to dexos 1(TM), the GF-5 standard will use a new fuel economy test, Sequence VID, which demands a statistically significant increase in fuel economy versus the Sequence VIB test that was used for GF-4. - It is expected that all dexos 1(TM) approved oils will be capable of meeting the GF-5 standard. However, not all GF-5 engine oils will be capable of meeting the dexos 1(TM) specification. - Like dexos(TM), the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers during October 2010, to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils. Corporate Average Fuel Economy (CAFE) Requirements Effect on Fuel Economy Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50 percent. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. New technology being introduced in GM vehicles designed to increase vehicle efficiency and fuel economy include direct injection, cam phasing, turbocharging and active fuel management (AFM). The demands of these new technologies on engine oil also are taken into consideration when determining new oil specifications. AFM for example can help to achieve improved fuel economy. However alternately deactivating and activating the cylinders by not allowing the intake and exhaust valves to open contributes to additional stress on the engine oil. Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. dexos 1(TM) will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. Using the right viscosity grade oil is critical for proper engine performance. Always refer to the Maintenance section of a vehicle Owner Manual for the proper viscosity grade for the engine being serviced. GM Oil Life System in Conjunction With dexos (TM) Supports Extended Oil Change Intervals To help conserve oil while maintaining engine protection, many GM vehicles are equipped with the GM Oil Life System. This system can provide oil change intervals that exceed the traditional 3,000 mile (4,830 km) recommendation. The dexos (TM) specification, with its requirements for improved oil robustness, compliments the GM Oil Life System by supporting extended oil change intervals over the lifetime of a vehicle. If all GM customers with GM Oil Life System equipped vehicles would use the system as intended, GM estimates that more than 100 million gallons of oil could be saved annually. GM dexos 2(TM) Information Center Website Refer to the following General Motors website for dexos 2(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 2(TM) Engine Oil Trademark and Icons Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 1905 The dexos (TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos (TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos (TM)specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 2(TM) engine oil. GM dexos 2(TM) Engine Oil Specification - dexos 2(TM) is approved and recommended by GM for use in Europe starting in model year 2010 vehicles, regardless of where the vehicle was manufactured. - dexos 2(TM) is the recommended service fill oil for European gasoline engines. Important The Duramax(TM) diesel engine is the exception and requires lubricants meeting specification CJ-4. - dexos 2(TM) is the recommended service fill oil for European light-duty diesel engines and replaces GM-LL-B-025 and GM-LL-A-025. - dexos 2(TM) protects diesel engines from harmful soot deposits and is designed with limits on certain chemical components to prolong catalyst life and protect expensive emission reduction systems. It is a robust oil, resisting degradation between oil changes and maintaining optimum performance longer. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Specifications > Capacity Specifications Engine Oil: Capacity Specifications TYPE.................................................................................................................................................... .......................................................................SG, SH Note: 1992-93 Syclone, and Typhoon engine oil must be Mobile 1 synthetic or equivalent CAPACITY, Refill: 4-cyl. 2.5L............................................................................................................... ..............................................................................2.8 Liters 3.0 Quarts Others................................... .............................................................................................................................................................. ...3.8 Liters 4.0 Quarts Capacity shown is without filter. When replacing filter, additional oil may be needed 1987-88 4.3L: Above 40°F (4°C).......................................................................................................... .....................................................................................................30‡ Above 0°F to (-18°C)................ .............................................................................................................................................................. ...................10W-30* Below 60°F (16°C).............................................................................................. ..........................................................................................................5W-30 1987-88 others, 1988-94 except Syclone & Typhoon: Above 40°F (4°C)............................................ .............................................................................................................................................................. .....30‡ Above 0°F to (-18°C)................................................................................................................ ...................................................................................10W-30 All temperatures................................... .............................................................................................................................................................. ..........5W-30* 1992-93 Syclone, Typhoon: All temperatures...................................................................................... .....................................................................................................................10W-30 *Preferred, except V6 4.3L ‡May be used when other recommended viscosities are unavailable Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1916 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1917 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1918 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1919 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1920 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1921 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1922 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1932 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1933 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1934 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1935 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1936 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1937 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1938 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pan, Engine > Component Information > Service and Repair Oil Pan: Service and Repair OIL PAN REPLACEMENT A one-piece type oil pan gasket is used Remove or Disconnect ( See Figure). 1. Negative battery cable. - Raise the vehicle and support with suitable safety stands. - Drain the engine oil. 2. Exhaust pipe at the exhaust manifolds. 3. Torque converter cover. 4. Starter. 5. Oil pan bolts, nuts, and reinforcements. 6. Oil pan and gasket. Clean - Gasket surfaces on the engine and oil pan. Inspect - Oil pan gasket for damage. Replace if necessary. Install or Connect (See Figure). - Apply sealant (GM P/N 1052080 or 12346141) or equivalent to the front cover to block joint and to the rear crankshaft seal to block joint. Apply the sealant for about 25 mm (1 inch) in both directions from each of the four corners. 1. Oil pan gasket to the oil pan. 2. Oil pan to the engine. NOTICE: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above conditions are not followed, parts or system damage could result. 3. Oil pan bolts nuts and reinforcements. Tighten Oil pan bolts to 11 N.m (100 lbs. in.). Oil pan nuts at corners to 23 N.m (17 lbs. ft.). 4. Starter. Refer to Starting and Charging. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pan, Engine > Component Information > Service and Repair > Page 1963 5. Torque converter cover. 6. Exhaust pipe to the manifolds. - Lower the vehicle. 7 Proper quantity and grade of engine oil. 8 Negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Locations Oil Pressure Gauge: Locations Coolant Temperature And Oil Pressure Sensor Locations Located on the top left side of the engine, near the distributor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate Oil Pressure Gauge: Testing and Inspection Gauge Readings Are Inaccurate 1. Remove lead from sensor, then connect tester J 33431-A or equivalent to sensor lead and ground. 2. If gauge responds accurately to tester, replace sensor. 3. If gauge does not respond accurately to tester, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 1969 Oil Pressure Gauge: Testing and Inspection Gauge Reads High 1. Disconnect lead from sensor, then turn ignition switch to the ON position and ground lead. 2. If gauge reads low, replace sensor. 3. If gauge reads high, locate and repair open circuit between sensor and gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 1970 Oil Pressure Gauge: Testing and Inspection Gauge Reads Low 1. Check oil level, add if necessary. 2. Turn ignition switch to the On position. 3. Remove oil pressure sensor lead at sensor, gauge should read high. 4. If gauge stays low, remove sensor lead at gauge. Gauge should read high. If gauge reads high, locate and repair short to ground between gauge and sensor. 5. If gauge still reads low, replace cluster. 6. With lead removed at sensor, connect an ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 7. If sensor reads significantly lower than 44 ohms with engine running, replace sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 1988 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 1989 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 1990 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 1991 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks use a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit--which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation > Page 1995 Oil Pressure Warning Lamp/Indicator: Testing and Inspection The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pump, Engine > Engine Oil Pressure > Component Information > Specifications Engine Oil Pressure: Specifications Normal Oil Pressure, psi ........................................................................ Minimum pressures: 25-50 lbs. @ 1200 RPM; 42-60 lbs. @ 2400-5000 RPM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Engine - Intake Manifold Inspection/Replacement Intake Manifold: Technical Service Bulletins Engine - Intake Manifold Inspection/Replacement INFORMATION Bulletin No.: 00-06-01-026C Date: February 03, 2010 Subject: Intake Manifold Inspection/Replacement After Severe Internal Engine Damage Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to include additional model years. Please discard Corporate Bulletin Number 00-06-01-026B (Section 06 - Engine). When replacing an engine due to internal damage, extreme care should be taken when transferring the intake manifold to the new Goodwrench service engine long block. Internal damage may result in the potential discharge of internal engine component debris in the intake manifold via broken pistons and/or bent, broken, or missing intake valves. After removing the intake manifold from the engine, the technician should carefully inspect all of the cylinder head intake ports to see if the valve heads are still present and not bent. Usually when the valve heads are missing or sufficiently bent, internal engine component debris will be present to varying degrees in the intake port of the cylinder head. If this debris is present in any of the cylinder head intake ports, the intake manifold should be replaced. This replacement is required due to the complex inlet runner and plenum configuration of most of the intake manifolds, making thorough and complete component cleaning difficult and nearly impossible to verify complete removal of debris. Re-installation of an intake manifold removed from an engine with deposits of internal engine component debris may result in the ingestion of any remaining debris into the new Goodwrench service engine. This may cause damage or potential failure of the new service engine. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Engine - Intake Manifold Inspection/Replacement > Page 2004 Intake Manifold: Technical Service Bulletins Engine - Use of Wacker RTV Sealant for Intake Manifold File In Section: 6 - Engine Bulletin No.: 67-61-17A Date: August, 1996 Subject: Use of Wacker T-330 RTV Sealant (Pronounced Vaucker T) Models: 1990-96 Buick Road master, Estate Wagon 1990-96 Cadillac Fleetwood 1990-96 Chevrolet Camaro, Caprice, Corvette, Impala SS 1990-92 Oldsmobile Custom Cruiser 1990-96 Pontiac Firebird with 4.3L, 5.7L Engine (VINs W, P, 5, 8 - RPOs L99, L98, LT1, LT4) 1990-96 Chevrolet and GMC Light and Medium Duty Trucks with 4.3L, 5.0L, 5.7L, 6.0L, 7.0L, 7.4L Engines (VINs W, Z, E H, K, M, N, P, R - RPOs L35, LB4, L03, L05, LS0, LR0, L19, L30, L31) This bulletin is being revised to add further Chevrolet models. Please discard Corporate Bulletin Number 67-61-17 (Section 6 - Engine). When installing the intake manifold, use a 5 mm (1/4 in.) thick bead of Wacker T-330 RTV, P/N 12346192, on the front and rear sealing areas between Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Engine - Intake Manifold Inspection/Replacement > Page 2005 the engine block and intake manifold. See Figures 1 and 2. Wacker T-330 RTV has improved adhesive abilities, is oxygen sensor safe, and is noncorrosive to ferrous metals. Wacker T-330 RW cannot be used in coolant sealing surface areas. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Page 2006 Intake Manifold: Specifications Intake Manifold Bolts 35 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Page 2007 Intake Manifold: Service and Repair Fig. 4 Intake Manifold Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Page 2008 Fig. 5 Intake Manifold Bolt Tightening Sequence 1. Disconnect battery ground cable. 2. Remove engine cover, air cleaner and heat stove tube. 3. Drain cooling system, then remove distributor assembly. 4. Remove cruise control transducer, if equipped. 5. Disconnect cruise control, TVS and accelerator cables, as required. 6. On models equipped with A/C, disconnect A/C compressor and position aside. 7. Remove engine oil filler tube from the alternator bracket. 8. Remove transmission dipstick tube from manifold, if equipped. 9. Remove idler pulley bracket and alternator brackets from manifold. 10. Disconnect fuel and vacuum lines and all electrical connectors from manifold and TBI unit. 11. Remove heater pipe, upper radiator hose, then the power brake vacuum pipe. 12. Disconnect coil wires, then the EGR vacuum line. 13. Disconnect sensors with bracket and wire harness form right side. 14. Remove intake manifold attaching bolts, then the intake manifold. 15. Reverse procedure to install, noting the following: a. Remove all traces of old sealant from cylinder head, block and manifold. b. Install gaskets on cylinder heads and apply a 3/16 inch bead of RTV sealant to front and rear ridges of cylinder case. Extend sealant 1/2 inch up each cylinder head to seal and retain side gaskets. c. Torque manifold attaching bolt A to 41 ft. lbs. and all other bolts to 35 ft. lbs. in sequence shown in Fig. 8. and. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Locations Oil Pressure Gauge: Locations Coolant Temperature And Oil Pressure Sensor Locations Located on the top left side of the engine, near the distributor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate Oil Pressure Gauge: Testing and Inspection Gauge Readings Are Inaccurate 1. Remove lead from sensor, then connect tester J 33431-A or equivalent to sensor lead and ground. 2. If gauge responds accurately to tester, replace sensor. 3. If gauge does not respond accurately to tester, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 2015 Oil Pressure Gauge: Testing and Inspection Gauge Reads High 1. Disconnect lead from sensor, then turn ignition switch to the ON position and ground lead. 2. If gauge reads low, replace sensor. 3. If gauge reads high, locate and repair open circuit between sensor and gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 2016 Oil Pressure Gauge: Testing and Inspection Gauge Reads Low 1. Check oil level, add if necessary. 2. Turn ignition switch to the On position. 3. Remove oil pressure sensor lead at sensor, gauge should read high. 4. If gauge stays low, remove sensor lead at gauge. Gauge should read high. If gauge reads high, locate and repair short to ground between gauge and sensor. 5. If gauge still reads low, replace cluster. 6. With lead removed at sensor, connect an ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 7. If sensor reads significantly lower than 44 ohms with engine running, replace sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks use a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit--which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation > Page 2020 Oil Pressure Warning Lamp/Indicator: Testing and Inspection The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Seals and Gaskets, Engine > Crankshaft Main Bearing Seal > Component Information > Service and Repair Crankshaft Main Bearing Seal: Service and Repair 1. Remove transmission from vehicle. 2. Remove clutch and flywheel, if equipped. 3. Insert suitable screwdriver into notches in seal retainer, then pry out oil seal. Use caution not to damage crankshaft sealing surface. 4. Clean sealing surface of crankshaft using non-abrasive cleaner. 5. Apply engine oil to inner and outer diameter of oil seal. 6. Install seal using seal installer tool No. J-35621, or equivalent. 7. Install clutch and flywheel, as required. 8. Install transmission and tighten transmission to engine bolts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Seals and Gaskets, Engine > Front Crankshaft Seal > Component Information > Service and Repair Front Crankshaft Seal: Service and Repair 1. Remove engine front cover. Refer to Engine/Timing Components/Timing Cover/Service and Repair/Front Cover Replace. See: Timing Components/Timing Cover/Service and Repair 2. Pry seal out of front cover using a suitable screwdriver, using caution not to scar the surface. 3. Drive new seal into position using seal installer tool No. J-35468, or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 2046 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 2047 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2048 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2049 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Balance Shaft > Component Information > Specifications Balance Shaft: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Journal Bearing Diameter Front .................................................................................................................................................... ...................................................... 2.1648-2.1654 Rear ...................................................................... ...................................................................................................................................... 1.4994-1.5000 Rear Bearing Journal Clearance ......................................................................................................... ........................................................ 0.0010-0.0036 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Timing Cover > Component Information > Service and Repair Timing Cover: Service and Repair 1. Remove fan belt, then crankshaft pulley. 2. Raise and support vehicle. 3. Remove torsional damper attaching bolt, then the torsional damper using puller tool No. J-23523, or equivalent. 4. Remove water pump. 5. Remove oil pan. 6. Remove front cover attaching bolts, then the front cover and gasket. Discard gasket. 7. Reverse procedure to install, noting the following: a. Install new front cover gasket. b. Tighten torsional damper to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Diagnostic Connector - Fuel Pump: Locations Engine Component Wiring, LH Side Located RH front of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations > Page 2062 C122, Fuel Pump Prime Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 2067 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 2068 Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Auto D 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 2069 Idle Speed: Adjustments CONTROLLED IDLE SPEED CHECK NOTE: Before performing this check, there should be no codes displayed, idle air control system has been checked and the ignition timing is correct. 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, refer to DIAGNOSIS BY SYMPTOM/DIAGNOSIS AND TESTING PROCEDURES/ROUGH, UNSTABLE OR INCORRECT IDLE. MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Man. N 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 2079 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 2085 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark 4.3L (M/L) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications > Page 2105 Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Locations Distributor And Coil 4.3L Engine Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation Distributor: Service and Repair Removal & Installation Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2111 Distributor And Coil 4.3L Engine Distributor And Coil 5.0L And 5.7L (TBI) Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2112 Distributor And Coil - 7.4L Engine Removal: NOTE:Verify ignition switch is "OFF". 1. Disconnect wiring harness connectors at side of distributor. 2. Remove coil wire and sparkplug wires on either the left or right side of the distributor. 3. Remove distributor cap by the two screws and set to side: A. Bring engine to TDC on the compression stroke for the #1 cylinder and align timing marks to 0~ . B. Scribe a mark on the distributor housing in line with the rotor. C. Scribe a mark on the engine in line with the rotor. D. Note position of the distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. Installation: NOTE:To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Install distributor and gasket (if applicable). 2. Install hold-down clamp and tighten bolt: ^ Bolt on the 2.8R to 35 Nm (26 lb. ft.). ^ Bolt on the 4.3Z, 5.0H, 5.7K & 7.4N to 35 Nm (25 lb. ft.) 3. Install distributor cap. 4. Connect wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2113 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components Removal: 1. With distributor removed, disconnect wires at module terminals 2. Remove roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Remove gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Remove distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. Installation: 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2114 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ............................................................... .045 inches Spark Plug Torque ............................................................................................................................... ..................................................... 15 Nm (11 lb. ft.) Spark Plug Type .................................................................................................................................. .............................................................. AC CR43TS NOTE: Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 2125 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 2126 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 2127 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Water Pump > Component Information > Service and Repair Water Pump: Service and Repair Fig. 16 Water Pump Replacement 1. Disconnect battery ground cable. 2. Drain cooling system. 3. Remove the serpentine drive belt. 4. Remove upper fan shroud, fan and fan clutch assembly, then the water pump pulley. 5. Remove water pump attaching bolts, then disconnect the heater hose from pump. 6. Remove the water pump, Fig. 18. 7. Remove old gasket material. 8. Reverse procedure to install, using suitable pipe sealant on bolt threads. Tighten water pump bolts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information Coolant: Technical Service Bulletins Cooling System - Coolant Recycling Information Bulletin No.: 00-06-02-006D Date: August 15, 2006 INFORMATION Subject: Engine Coolant Recycling and Warranty Information Models: 2007 and Prior GM Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER Vehicles 2005-2007 Saab 9-7X Attention: Please address this bulletin to the Warranty Claims Administrator and the Service Manager. Supercede: This bulletin is being revised to adjust the title and Include Warranty Information. Please discard Corporate Bulletin Number 00-06-02-006C (Section 06 - Engine/Propulsion System). Coolant Reimbursement Policy General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words: if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of GM Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Licensed Approved DEX-COOL(R) Providers Important: USE OF NON-APPROVED VIRGIN OR RECYCLED DEX-COOL(R) OR DEVIATIONS IN THE FORM OF ALTERNATE CHEMICALS OR ALTERATION OF EQUIPMENT, WILL VOID THE GM ENDORSEMENT, MAY DEGRADE COOLANT SYSTEM INTEGRITY AND PLACE THE COOLING SYSTEM WARRANTY UNDER JEOPARDY. Shown in Table 1 are the only current licensed and approved providers of DEX-COOL(R). Products that are advertised as "COMPATIBLE" or "RECOMMENDED" for use with DEX-COOL(R) have not been tested or approved by General Motors. Non-approved coolants may degrade the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2136 coolant system integrity and will no longer be considered a 5 yr/150,000 mile (240,000 km) coolant. Coolant Removal Services/Recycling The tables include all coolant recycling processes currently approved by GM. Also included is a primary phone number and demographic information. Used DEX-COOL(R) can be combined with used conventional coolant (green) for recycling. Depending on the recycling service and/or equipment, it is then designated as a conventional 2 yr/30,000 mile (50,000 km) coolant or DEX-COOL(R) 5 yr/150,000 mile (240,000 km) coolant. Recycled coolants as designated in this bulletin may be used during the vehicle(s) warranty period. DEX-COOL(R) Recycling The DEX-COOL(R) recycling service listed in Table 2 has been approved for recycling waste engine coolants (DEX-COOL) or conventional) to DEX-COOL(R) with 5 yr/150,000 mile (240,000 km) usability. Recycling Fluid Technologies is the only licensed provider of Recycled DEX-COOL(R) meeting GM6277M specifications and utilizes GM approved inhibitor packages. This is currently a limited program being monitored by GM Service Operations which will be expanded as demand increases. Conventional (Green) Recycling Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2137 Processes shown in the Table 3 are capable of recycling waste engine coolants (DEX-COOL(R) or conventional) to a conventional (green) coolant. Recycling conventional coolant can be accomplished at your facility by a technician using approved EQUIPMENT (listed by model number in Table 3), or by an approved coolant recycling SERVICE which may recycle the coolant at your facility or at an offsite operation. Refer to the table for GM approved coolant recyclers in either of these two categories. Should you decide to recycle the coolant yourself, strict adherence to the operating procedures is imperative. Use ONLY the inhibitor chemicals supplied by the respective (GM approved) recycling equipment manufacturer. Sealing Tablets Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage. Water Quality The integrity of the coolant is dependent upon the quality of DEX-COOL(R) and water. DEX-COOL(R) is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL(R) with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL(R). "Pink" DEX-COOL(R) DEX-COOL(R) is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL(R), some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval. Back Service Only use DEX-COOL(R) if the vehicle was originally equipped with DEX-COOL(R). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2138 Contamination Mixing conventional green coolant with DEX-COOL(R) will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL(R) and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL(R). After 5 years/150,000 miles (240,000 km) After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL(R) and has not had problems with contamination from non-DEX-COOL(R) coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km) Equipment (Coolant Exchangers) The preferred method of performing coolant replacement is to use a coolant exchanger. A coolant exchanger can replace virtually all of the old coolant with new coolant. Coolant exchangers can be used to perform coolant replacement without spillage, and facilitate easy waste collection. They can also be used to lower the coolant level in a vehicle to allow for less messy servicing of cooling system components. It is recommended that you use a coolant exchanger with a vacuum feature facilitates removing trapped air from the cooling system. This is a substantial time savings over repeatedly thermo cycling the vehicle and topping-off the radiator. The vacuum feature also allows venting of a hot system to relieve system pressure. Approved coolant exchangers are available through the GMDE (General Motors Dealer Equipment) program. For refilling a cooling system that has been partially or fully drained for repairs other than coolant replacement, the Vac-N-Fill Coolant Refill Tool (GE-47716) is recommended to facilitate removal of trapped air from the cooling system during refill. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2139 Coolant: Technical Service Bulletins Engine Coolant - Information on Back Service File In Section: 6 - Engine Bulletin No: 53-62-02 Date: November, 1995 Subject: DEX-COOL(TM) Engine Coolant - Information on Back service Models: 1994-95 Passenger Cars and Trucks A new extended-life engine coolant called DEX-COOL(TM) is currently being used in all General Motors' vehicles (excluding Chevrolet Geo and Saturn). Refer to bulletin 53-62-01 for general service information. Backservice DEX-COOL(TM) may be used in General Motors vehicles originally built with conventional (green) coolant with the following considerations: ^ Vehicles eligible for back service are 1994 and 1995 models (excluding 1994 J Body with 4 cylinder engines). ^ The service interval for DEX-COOL(TM) introduced into an older model vehicle originally built with "green" coolant will be 2 years/30,000 miles (50,000 Km) (not 5 years/100,000 miles (160,000 Km)). ^ All the "green" coolant must be removed from the cooling system by means of a system flush. This may be accomplished with a water flushing device or a GMDE waterless coolant changer (use a unit dedicated to "green" coolant, not DEX-COOL TM). Important: When using a GMDE waterless coolant changer, conduct the procedure twice, once with water, and once with DEX-COOL(TM) Backservice with DEX-COOL(TM) is advocated because of enhanced water pump seal durability experienced with this coolant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2140 Coolant: Technical Service Bulletins Warranty - Recycled Engine Coolant Policy Group Ref.: Warranty Administration Bulletin No.: 310504 Date: February, 1994 WARRANTY ADMINISTRATION SUBJECT: RECYCLED ENGINE COOLANT POLICY MODELS: 1994 AND PRIOR PASSENGER CARS AND TRUCKS ATTENTION: WARRANTY CLAIMS ADMINISTRATOR AND SERVICE MANAGER General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. For detailed information on GM approved engine coolant recycling equipment guidelines refer to the following bulletins: Cadillac 93-1-18, GMC Truck 93-6B-34, Chevrolet 93-73-6B, Pontiac 93-6-18, Oldsmobile 1-93-43, Buick 93-6B-1 (Corporate Number 236203). Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial to assure that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words, if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2141 Coolant: Technical Service Bulletins Coolant - Information on Propylene Glycol Usage File In Section: 6 - Engine Bulletin No.: 43-62-01B Date: April, 1995 Subject: Propylene Glycol Engine Coolant Models: 1994 and Prior Passenger Cars and Trucks This bulletin is being revised to reflect most current information on propylene glycol engine coolant. Please discard Corporate Bulletin Number 4362O1A (Group Reference 6 - Engine). General Motors has been reviewing data supplied on the performance of propylene glycol engine coolant in GM vehicles. It is our conclusion that propylene glycol engine coolant will perform adequately under most vehicle operating conditions. As a result, propylene glycol engine coolant (meeting performance specification GM 1825M) may be used in GM vehicles and will not affect the warranty coverage. Prior to adding propylene glycol engine coolant to the cooling system, all the existing (ethylene glycol) coolant must be removed. This can be accomplished either by utilizing water-based coolant flushing equipment or "waterless quick change" equipment available in the GMDE program. As with any coolant change procedure, be sure to thoroughly purge the heater core and block as well as the radiator before attempting to convert the system to propylene glycol coolant. Freeze/Boil point levels are different for propylene glycol than for ethylene glycol engine coolant. To accurately determine freeze/boil protection level, it is imperative that coolants not be mixed. Removing all the used coolant as previously discussed resolves this concern. Freeze protection of propylene glycol cannot be determined using a standard hydrometer. Rather, a refractometer or test strip must be used. Propylene glycol engine coolants may be recycled in the same manner as conventional ethylene glycol coolant. No adverse effects will be encountered if these coolants are mixed prior to recycling, however, the ratio of propylene glycol coolant to ethylene glycol coolant should be kept low to minimize the effects on freeze point measurements. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Page 2142 Coolant: Specifications Coolant Capacity, Qts. Less A/C [03] ....................................................................................................................................... ....................................................................... 13.5 With A/C [03] ....................................................... ...................................................................................................................................................... 13.5 Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 [03] Add 3.0 qts. if equipped w/ rear heater. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 2148 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Blade > Component Information > Service Precautions > Technician Safety Information Fan Blade: Technician Safety Information WARNING: Do not operate engine until fan has first been inspected for cracks and/or separations. If a fan blade is found to be bent or damaged in any way, do not attempt to repair or reuse damaged part. Proper balance is essential in fan assembly operation. Balance cannot be assured once a fan assembly has been found to be bent or damaged and failure may occur during operation, creating an extremely dangerous condition. Always replace damaged fan assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Blade > Component Information > Service Precautions > Technician Safety Information > Page 2154 Fan Blade: Vehicle Damage Warnings WARNING: Do not operate engine until fan has first been inspected for cracks and/or separations. If a fan blade is found to be bent or damaged in any way, do not attempt to repair or reuse damaged part. Proper balance is essential in fan assembly operation. Balance cannot be assured once a fan assembly has been found to be bent or damaged and failure may occur during operation, creating an extremely dangerous condition. Always replace damaged fan assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > A/T - Intermittent Downshift/Slip/Cycling Diagnosis Fan Clutch: Technical Service Bulletins A/T - Intermittent Downshift/Slip/Cycling Diagnosis File In Section: 07 Transmission/Transaxle Bulletin No.: 99-07-30-016B Date: October, 2002 INFORMATION Subject: Diagnostic Information For Intermittent Transmission Downshift, Slip, Busy/cycling TCC or Noisy Cooling Fan Models: 1999-2000 Cadillac Escalade 2002-2003 Cadillac Escalade, Escalade EXT 1988-2003 Chevrolet Astro, Blazer, S-10, Silverado, Suburban 1989-2003 Chevrolet/Geo Tracker 1995-2003 Chevrolet Tahoe 1996-2003 Chevrolet Express 1988-1994 GMC S-15 1988-1999 GMC Suburban 1988-2003 GMC Safari, Sierra 1995-2003 GMC Sonoma, Yukon, Yukon XL 1996-2003 GMC Savana 1999-2001 GMC Envoy 1991-2001 Oldsmobile Bravada 2003 HUMMER H2 with Air Conditioning This bulletin is being revised to change the Model information and text. Please discard Corporate Bulletin Number 99-07-30-016A (Section 07 - Transmission/Transaxle) Some customers may comment that at times the transmission seems to slip, or that there is a loud roar from the engine with slow acceleration. This condition is most noticeable after the vehicle has sat idle for 12 or more hours, or on hot days when the A/C is on and the vehicle moves slowly with traffic. Typical comments from customers may include the following conditions: ^ Intermittent slipping ^ Intermittent downshift followed by an upshift, both with no apparent reason ^ Busyness or cycling of the TCC (torque converter clutch) at steady throttle conditions and on a level roadway ^ Noisy cooling fan The type of concern described above requires further definition. The customer should be asked the following questions: ^ Is the situation more pronounced with higher vehicle loads such as when pulling a trailer? ^ Do warmer ambient temperatures make the situation more pronounced? ^ When the condition occurred, did you have the A/C on, and were you driving in stop and go city traffic? ^ Does the condition exhibit itself on the first start-up after sitting more than eight hours? If the customer indicates that these conditions apply, and your observation confirms that the vehicle is operating properly, provide the customer with the vehicle operating description included at the end of this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. Diagnostic Aids Cooling fan operation or the resulting sound varies. The cooling fan clutch may be described as a continuously variable clutch. If the vehicle engine is running, the fan blade is always turning unless the fan clutch is non-functional. The speed of the fan in relation to engine speed is temperature dependent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > A/T - Intermittent Downshift/Slip/Cycling Diagnosis > Page 2159 Maximum fan speed (air flow and related fan noise) through the engine compartment is experienced under two conditions. 1. When the vehicle sits in an unused condition for several hours, the viscous fluid within the thermostatic fan clutch assembly migrates and fully engages the clutch of the fan. After a short drive, the viscous fluid will migrate to the storage area in the fan clutch and the fan clutch will slip, reducing the noise (roar of the fan). This is normal thermostatic fan clutch operation. 2. When the engine is running, and the air being drawn by the fan or pushed through the radiator from the vehicle movement reaches a high enough temperature, the fan clutch will fully engage the fan clutch, drawing additional air through the radiator to lower the engine coolant temperature and A/C refrigerant temperature. When the cooling fan clutch fully engages, fan noise increases (for example; this is the same as switching an electric household fan from low to high speed). Some customers have interpreted this sound increase to be an increase in the engine RPM due to transmission downshift, transmission slipping, or TCC cycling. As the engine coolant temperature decreases, the fan clutch will begin to slip, lowering the actual speed of the fan blade and the resultant sound. Service Procedure When diagnosing an intermittent transmission downshift, slip, or busy/cycling TCC, follow these steps: 1. Verify the transmission fluid level and the fluid condition. Refer to the Automatic Transmission sub-section of the appropriate Service Manual. 2. Test drive the vehicle under the conditions described by the customer (ambient temperature, engine coolant temperature, trailering, etc.). It may be necessary to partially restrict airflow to the radiator in order to raise the engine coolant temperature to match the customer's conditions. 3. Monitor the engine RPM and the engine coolant temperature using a scan tool. 4. Listen for an actual increase in the engine RPM. Use either the vehicle tachometer (if equipped), the Tech 2 RPM or transmission slip speed as an indicator, rather than just the sound. If the engine RPM display on the tachometer or the Tech 2 increases, verify the scan tool RPM and coolant temperature readings. If the noise increase is due to the engagement of the fan, the engine RPM will not increase and the engine coolant temperature will begin to decrease after the fan engages. As the fan runs, the engine coolant temperature will drop and the fan will disengage, reducing noise levels. The engine RPM will not decrease. This cycle will repeat as the engine coolant temperature rises again. If the above procedure shows the condition to be cooling fan-related, no further action is necessary. The vehicle should be returned to the customer and the condition explained. If the above procedure shows the condition to be other than cooling fan-related, refer to the Automatic Transmission sub-section of the appropriate Service Manual for transmission diagnosis information. The following information regarding the operation of the engine cooling fan should be photocopied and given to the customer. Intermittent Transmission Downshift All light duty trucks are equipped with a thermostatic engine cooling fan. This fan is designed to provide greater fuel efficiency and quieter operation than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool (it the engine has been run in the last few hours), the clutch allows the fan to "slip" or turn at a speed slower than the engine. By turning at a slower speed, the fan uses less horsepower, which saves fuel, and is quieter. When the engine temperature reaches a preset temperature or if the engine has not been run for several hours, the fan "engages" and turns at the same speed as the engine. "Engagement" of the fan provides increased airflow through the radiator to cool the engine. As the airflow increases, fan operation becomes clearly audible. This increase in noise can easily be mistaken for an increase in engine RPM and may be incorrectly blamed on the automatic transmission. When operating an unloaded vehicle in cooler ambient temperatures, the thermostatic clutch usually won't fully engage. However, if the vehicle is pulling a trailer, is heavily loaded or is operated at high ambient temperatures, the thermostatic fan clutch may cycle on and off as the engine coolant temperature rises and falls. The sound of fan operation under the conditions described above is a sign that the cooling system on your vehicle is working correctly. Replacement or modification of the cooling system or the transmission parts will not change or reduce the noise level. Attempts to reduce this noise may cause you, the customer, to believe that your vehicle is not reliable and will inconvenience you by causing your vehicle to be out of service. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > A/T - Intermittent Downshift/Slip/Cycling Diagnosis > Page 2160 DISCLAIMER Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > Page 2161 Fan Clutch: Description and Operation Fan Drive Clutch Assembly Variable Speed Fan W/Bi-Metallic Coiled Thermostatic Spring The fan drive clutch, Fig. 1, is a fluid coupling containing silicone oil. Fan speed is regulated by the torque-carrying capacity of the silicone oil. The more silicone oil in the coupling, the greater the fan speed, and the less silicone oil, the slower the fan speed. The type of fan drive clutch in use is a coiled bimetallic thermostatic spring, Fig. 2. The fan drive clutch uses a heat-sensitive, coiled bimetallic spring connected to an opening plate which regulates the flow of silicone oil into the coupling from a reserve chamber. The silicone oil is returned to the reserve chamber through a bleed hole when the valve is closed. This unit causes the fan speed to increase with a rise in temperature and to decrease as temperature decreases. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak Fan Clutch: Testing and Inspection Clutch Fluid Leak Small fluid leaks do not generally affect the operation of the unit. These leaks generally occur around the area of the bearing assembly, but if the leaks appear to be excessive, engine overheating may occur. Clutch and fan free-wheeling can cause overheating. To check for clutch and fan free-wheeling, turn the motor "OFF." Spin the fan and clutch assembly by hand. If the fan spins five or more times before it stops, replace the clutch. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak > Page 2164 Fan Clutch: Testing and Inspection Engine Overheating 1. Start with cool engine to ensure complete fan clutch disengagement. 2. If fan and clutch assembly free wheels with no drag (revolves more than five times when spun by hand), replace clutch. If clutch performs properly with slight drag, proceed to following step. 3. Position thermometer so it is located between fan blades and radiator, noting the following: a. Insert thermometer sensor through one of existing holes in fan shroud or place between radiator and shroud. It may be necessary to drill a 3/16 inch hole in fan shroud to insert thermometer. b. Check for adequate clearance between fan blades and thermometer sensor before starting engine, as damage could occur. 4. With thermometer in position, cover radiator grill sufficiently to induce high engine temperature. 5. Start engine, then turn on air conditioning and operate at 2000 RPM. 6. Observe thermometer reading when clutch disengages, noting the following: a. It will take approximately five to ten minutes for temperature to become high enough to allow engagement of fan clutch. This will be indicated by a 5-15 degrees F drop in thermometer reading. b. If clutch did not engage between 150-195 degrees F, unit should be replaced. Ensure fan clutch was disengaged at beginning of test. c. If no sharp increase in fan noise or temperature drop was observed and fan noise level was constantly high from start of test to 190 degrees F, unit should be replaced. Do not continue this test past thermometer reading of 190 degrees F to prevent engine overheating. 7. As soon as clutch engages, remove radiator grill cover and turn A/C off to assist in engine cooling. Run engine at approximately 1500 RPM. 8. After several minutes, fan clutch should disengage as indicated by reduction in fan speed and roar. If fan clutch fails to function as described, replace it. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak > Page 2165 Fan Clutch: Testing and Inspection Fan Clutch Noise Fan clutch noise can sometimes be noticed when clutch is engaged for maximum cooling. Clutch noise is also noticeable within the first few minutes after starting engine while clutch is redistributing the silicone fluid back to its normal, disengaged operating condition after settling for long periods of time (overnight). However, continuous fan noise or an excessive roar indicates the clutch assembly is locked-up due to internal failure. This condition can be checked by attempting to manually rotate fan. If fan cannot be rotated manually or there is a rough, abrasive feel as fan is rotated, the clutch should be replaced. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak > Page 2166 Fan Clutch: Testing and Inspection Fan Looseness Lateral movement can be observed at the fan blade tip under various temperature conditions because of the type bearing used. This movement should not exceed 1/4 inch (6.5 mm) as measured at the fan tip. If this lateral movement does not exceed specifications, there is no cause for replacement. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Page 2167 Fan Clutch: Service and Repair To prevent silicone fluid from draining into fan drive bearing, do not store or place drive unit on bench with rear of shaft pointing downward. The coil spring type fan clutch cannot be disassembled, serviced or repaired. If it does not function properly, it must be replaced with a new unit. To replace the fan clutch, use the following procedure: 1. Remove the radiator fan shroud. 2. Unfasten the unit from the water pump, then remove the assembly from vehicle. 3. Separate fan from fan clutch. 4. Reverse procedure to install, noting the following: a. Ensure mating surfaces of water pump hub and fan clutch hub are smooth and free of any burrs. b. Align yellow reference marks on water pump hub and fan clutch hub. c. Torque nuts to 18 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 2174 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2177 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2178 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2179 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2180 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2181 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2182 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2183 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2184 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2185 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2186 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2187 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2188 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2189 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2190 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2191 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2192 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2193 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2194 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2195 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2196 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2197 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2198 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2199 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2200 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2201 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2202 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2203 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2204 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2205 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2206 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2207 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2208 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2209 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2210 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor Temperature Sensor (Gauge): Locations Engine Coolant Temperature (ECT) Gage Sensor Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 2215 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 2216 Engine Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Control Valve > Component Information > Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) Heater Control Valve: Diagrams Actuators and Control Schematic (With A/C) Control Assembly Operating Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 2222 Schematic Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 2223 Heater Control Valve: Diagrams Vacuum Harness Routing Vacuum Hose Routing, Engine Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 2224 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators Heater Core: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2229 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2230 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core Heater Core: Service and Repair Front Heater Core Removal Heater-Defroster Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2233 Heater Assembly Component View REMOVE OR DISCONNECT 1. Engine coolant. 2. Heater hoses. 3. Instrument panel lower filler. 4. Floor air outlet duct. 5. Outlet duct screws. 6. Windshield defrost outlet duct. 7. Case cover screws. 8. Heater case cover. 9. Heater core screws. 10. Heater core. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2234 11. Seals. Installation Heater-Defroster Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2235 Heater Assembly Component View INSTALL OR CONNECT 1. Seals. 2. Heater core. 3. Heater core screws. 4. Heater case cover. 5. Case cover screws. 6. Windshield defrost outlet duct. 7. Outlet duct screws. ^ Tighten screws to 1.9 Nm (17 lb in). 8. Floor air outlet duct. 9. Instrument panel lower filler. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2236 10. Heater hoses. 11. Engine coolant. ^ Check the system for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2237 Heater Core: Service and Repair Rear Removal Figure 20-Rear Heater Component View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2238 Figure 21-Heater Wiring-Resistor Replacement REMOVE OR DISCONNECT 1. Coolant from the radiator. 2. Negative battery cable. 3. Clamps from the heater pipes. 4. Screws. 5. Cover. 6. Screws. 7. Strap. 8. Core. 9. Seals from the core. Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2239 Figure 20-Rear Heater Component View Figure 21-Heater Wiring-Resistor Replacement INSTALL OR CONNECT 1. Seals to the core. 2. Core. 3. Strap. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 2240 4. Screws. 5. Cover. 6. Screws. 7. Pipes to the core. 8. Clamps to the heater pipes. 9. Negative battery cable. 10. Coolant in radiator. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Locations > Heater Hose Routing Heater Hose: Locations Heater Hose Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 2245 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 2246 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 2247 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 2248 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 2255 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot Temperature Gauge: Testing and Inspection Gauge Does Not Move From Cold When Engine Is Hot This condition is generally caused by a blown fuse, open circuit or faulty sensor. 1. Check fuse, replace if necessary. 2. Turn ignition switch to On position, then remove lead at sensor unit. 3. Connect test lamp from sensor lead to ground, lamp should glow. Short sensor lead to ground, gauge should indicate "Hot." 4. If gauge indicated HOT, check lead on sensor. If satisfactory, replace sensor. If gauge indicates COLD, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2260 Temperature Gauge: Testing and Inspection Gauge Indicates Hot When Engine Is Cold This condition is generally caused by a shorted or grounded circuit. 1. Remove sensor lead at sensor unit. Gauge should move to COLD position, if not check unit for a external short. If no external short is found, replace sensor. 2. If gauge stays HOT, check for a short circuit in gauge to sensor wiring. If circuit is satisfactory, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2261 Temperature Gauge: Testing and Inspection Gauge Reads High 1. Remove lead at sensor, measure resistance using an ohmmeter. 2. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 3. If resistance is not within specifications, replace sensor. 4. Disconnect lead at sensor and gauge, check for a high resistance using an ohmmeter. Repair wiring if necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2262 Temperature Gauge: Testing and Inspection Gauge Reads Low 1. Ensure terminals are clean and connections are tight. 2. Remove lead at sensor, measure resistance using an ohmmeter. 3. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 4. If resistance is not within specifications, replace sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation Temperature Warning Lamp/Indicator: Description and Operation A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation > Page 2266 Temperature Warning Lamp/Indicator: Testing and Inspection If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators Radiator: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2271 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2272 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2273 Radiator: Technical Service Bulletins Cooling - Radiator Repair/Replacement Guidelines File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-02-017 Date: October, 1999 INFORMATION Subject: Radiator Repair/Replacement Guidelines Models: 2000 and Prior Passenger Cars and Trucks If repair of an aluminum/plastic radiator is required, it is recommended that the following guidelines be followed: For Vehicles Under Warranty For aluminum/plastic radiators that have damage to the face of the core including bent fins, punctures, cuts, leaking tubes or header tubes, the aluminum radiator core section should be replaced with a new one. In these cases, if both of the plastic tanks are not damaged, they can be reused with the new core. If one or both of the plastic tanks are damaged along with the core, it is recommended that a complete new radiator assembly be installed. Warranty repairs for leaks at the tank to header (gasket leaks), broken/cracked plastic tanks, cross threaded or leaking oil coolers should be repaired without replacing the complete radiator. This type of repair should be handled by the radiator repair facility in your area. Many of these radiator repair facilities are members of the National Automotive Radiator Service Association (NARSA) who follow industry and General Motors guidelines when repairing radiators. These facilities have the special tools, tanks and pressurizing equipment needed to properly test the repaired radiator prior to returning it to the dealership. Many of these facilities receive the repair components directly from General Motors. The sublet expense for a new radiator or the repair of the radiator under warranty should be handled following normal procedures. For Vehicles No Longer Under Warranty The GM released epoxy repair kit referenced in previous publications is no longer available. Repairs to the radiator, rather than replacement, is strictly at the owner's discretion. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Page 2274 Grounds To Radiator Support Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Page 2275 Radiator: Service and Repair 1. Disconnect battery ground cable, then drain coolant from radiator. 2. Remove upper fan shroud and radiator hoses. 3. Using quick disconnect tool No. J-37088-2A, or equivalent, disconnect transmission fluid cooler pipes. 4. Disconnect engine oil cooler pipes. 5. Remove overflow hose and radiator. 6. Reverse procedure to install. Check fluid levels. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cap > Component Information > Specifications Radiator Cap: Specifications Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 2286 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2289 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2290 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2291 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2292 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2293 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2294 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2295 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2296 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2297 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2298 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2299 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2300 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2301 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2302 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2303 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2304 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2305 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2306 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2307 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2308 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2309 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2310 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2311 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2312 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2313 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2314 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2315 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2316 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2317 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2318 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2319 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2320 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2321 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2322 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor Temperature Sensor (Gauge): Locations Engine Coolant Temperature (ECT) Gage Sensor Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 2327 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 2328 Engine Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot Temperature Gauge: Testing and Inspection Gauge Does Not Move From Cold When Engine Is Hot This condition is generally caused by a blown fuse, open circuit or faulty sensor. 1. Check fuse, replace if necessary. 2. Turn ignition switch to On position, then remove lead at sensor unit. 3. Connect test lamp from sensor lead to ground, lamp should glow. Short sensor lead to ground, gauge should indicate "Hot." 4. If gauge indicated HOT, check lead on sensor. If satisfactory, replace sensor. If gauge indicates COLD, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2333 Temperature Gauge: Testing and Inspection Gauge Indicates Hot When Engine Is Cold This condition is generally caused by a shorted or grounded circuit. 1. Remove sensor lead at sensor unit. Gauge should move to COLD position, if not check unit for a external short. If no external short is found, replace sensor. 2. If gauge stays HOT, check for a short circuit in gauge to sensor wiring. If circuit is satisfactory, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2334 Temperature Gauge: Testing and Inspection Gauge Reads High 1. Remove lead at sensor, measure resistance using an ohmmeter. 2. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 3. If resistance is not within specifications, replace sensor. 4. Disconnect lead at sensor and gauge, check for a high resistance using an ohmmeter. Repair wiring if necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2335 Temperature Gauge: Testing and Inspection Gauge Reads Low 1. Ensure terminals are clean and connections are tight. 2. Remove lead at sensor, measure resistance using an ohmmeter. 3. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 4. If resistance is not within specifications, replace sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation Temperature Warning Lamp/Indicator: Description and Operation A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation > Page 2339 Temperature Warning Lamp/Indicator: Testing and Inspection If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Thermostat, Engine Cooling > Component Information > Specifications Thermostat: Specifications Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Thermostat, Engine Cooling > Component Information > Specifications > Page 2343 Thermostat: Service and Repair 1. Drain cooling to level below thermostat. 2. Remove thermostat housing bolt. 3. Remove outlet and gasket. 4. Remove thermostat. 5. Reverse procedure to install. Tighten to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Water Pump > Component Information > Service and Repair Water Pump: Service and Repair Fig. 16 Water Pump Replacement 1. Disconnect battery ground cable. 2. Drain cooling system. 3. Remove the serpentine drive belt. 4. Remove upper fan shroud, fan and fan clutch assembly, then the water pump pulley. 5. Remove water pump attaching bolts, then disconnect the heater hose from pump. 6. Remove the water pump, Fig. 18. 7. Remove old gasket material. 8. Reverse procedure to install, using suitable pipe sealant on bolt threads. Tighten water pump bolts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations Exhaust System With Catalytic Converter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2351 Catalytic Converter: Description and Operation Catalytic Converters CAUTION: Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2352 NOTE: When jacking or lifting vehicle from frame side rails, be certain lift pads DO NOT contact catalytic converter or damage to converter may result. The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, entering the atmosphere. The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains unchanged, ready to repeat the process. This device sometimes requires the use of heat shields, due to its high operating temperatures. The heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs, are: single bed monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three-way (reduction) catalyst. The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The three-way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three-way catalysts. A fill pipe restrictor is used on catalytic converter equipped vehicles, to prevent the larger service station pump nozzle, used for leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalysts, rendering them ineffective, the use of unleaded fuels is mandatory in catalytic converter equipped vehicles. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2353 Catalytic Converter: Testing and Inspection RESTRICTED EXHAUST TEST Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedure(s) may be used for diagnosis: Exhaust System Check CHECK AT A.I.R. PIPE - Remove the rubber hose at the exhaust manifold A.I.R. pipe check valve and remove check valve. - Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device. - Insert the nipple into the exhaust manifold A.I.R. pipe. CHECK AT 02 SENSOR - Carefully remove O2 sensor. - Install Exhaust Backpressure Tester in place of 02 sensor. - After completing the diagnosis described below, be sure to coat threads of 02 sensor with anti-seize compound prior to re-installation. DIAGNOSIS - With the engine idling at normal operating temperature, transaxle in park or neutral, observe the exhaust system backpressure reading on the gauge. The reading should not exceed .5 psi or 3.4 kPa. Increase engine speed to 3000 rpm and observe gauge. The reading should not exceed .75 psi or 5 kPa. - If the backpressure exceeds the given specifications, a restricted exhaust system is indicated. - Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure. - If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced. WITH VACUUM GAUGE Engine at normal operating temperature: Connect a vacuum gauge to any convenient vacuum port on intake manifold. - Run engine at 1000 rpm and record vacuum reading. - Increase rpm slowly to 2500 rpm. Note vacuum reading at a steady 2500 rpm - If vacuum at 2500 rpm decreases more than 3" Hg, from reading at 1000 rpm, the exhaust system should be inspected for restrictions - Disconnect exhaust pipe from engine and repeat Step 2 & 3. If vacuum still drops more than 3" Hg, with exhaust disconnected, check for exhaust manifold restriction and valve timing. THERMAL TEST Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2354 Use a pyrometer to measure the temperature difference between the inlet and outlet. A warm and properly working catalytic converter will show about 100 degrees hotter at the outlet. NOTE:A fuel system that is running rich will not produce a catalyst and will indicate little or no temperature variation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > Customer Interest for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Exhaust Crossover Pipe: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > Customer Interest for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2363 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Exhaust Crossover Pipe: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2369 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Manifold > Component Information > Service and Repair Exhaust Manifold: Service and Repair Fig. 9 Exhaust Manifold Replacement RIGHT 1. Disconnect battery ground cable. 2. Remove engine cover, then raise and support vehicle. 3. Remove exhaust pipe from exhaust manifold, then lower vehicle. 4. Remove heat stove pipe. 5. Remove dipstick tube bracket from manifold. 6. Remove AIR hoses from check valve. 7. Remove exhaust manifold attaching bolts, washers and tab washers, then the exhaust manifold, Fig. 9. 8. Reverse procedure to install. Bend tab washers over heads of all bolts. LEFT 1. Disconnect battery ground cable. 2. Remove engine cover, then raise and support vehicle. 3. Remove exhaust pipe from exhaust manifold, then lower vehicle. 4. Disconnect oxygen sensor electrical connector. Do not remove sensor unless it must be replaced. 5. Remove power steering pump and alternator brackets from manifold. 6. Remove AIR hoses from check valve. 7. Remove exhaust manifold attaching bolts, washers and tab washers, then the heat shield and exhaust manifold, Fig. 9. 8. Reverse procedure to install. Bend tab washers over heads of all bolts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2380 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2381 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2382 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2383 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2384 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2385 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2386 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2387 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2388 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2389 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 2390 Powertrain Control Module Mounting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description Engine Control Module: Diagrams Connector Description PCM Connector Terminal End View (1 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2393 PCM Connector Terminal End View (2 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2394 PCM Connector Terminal End View (3 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2395 PCM Connector Terminal End View (4 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2396 Engine Control Module: Diagrams C204 (32-Pin Blue) C204, Powertrain Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2397 C204, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2398 Engine Control Module: Diagrams C288 (32-Pin Red) C288, Powertrain Control Module C288, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2399 Engine Control Module: Description and Operation OPERATION: The control module is located in the passenger compartment and is the control center of the Computer Command Control system. The control module constantly receives information from various sensors. The computer performs the diagnostic functions of the system. The computer can recognize operational problems and alert the driver through the Malfunction Indicator Lamp (MIL) (Service Engine Soon light). The computer stores a trouble code which identifies the problem area to diagnose and repair. The computer is designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The computer has a learning ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected to clear trouble codes or for repair, the learning process has to begin all over again, and a change may be noticed in the driving performance of the vehicle. To reset the vehicles learning ability, make sure the engine is at operating temperature and operate the vehicle at part throttle, moderate acceleration, and idle conditions, until normal performance returns. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2400 Engine Control Module: Service and Repair Control Module Mounting CAUTION: [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, DO NOT touch the connector pins or soldered components on the circuit boards. NOTE: When replacing a production control module with a service controller, transfer the broadcast DTC and production control module part number to the controller label. DO NOT record information on the access cover. REMOVAL: 1. Disconnect the negative battery terminal. 2. Remove passenger kick panel. 3. Disconnect control module harness connectors. 4. Remove control module retainer and control module. 5. Remove brackets and modules if equipped.. 6. Remove access cover and PROM (MEM-CAL). INSTALLATION: 1. Install PROM (MEM-CAL) and access cover on to new control module. 2. Install mounting brackets and module(s) if equipped. 3. Connect control module harness connectors. 4. Install control module and retainer. 5. Install passenger kick panel. 6. Connect the negative battery terminal. 7. Perform functional check. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Control Unit > Component Information > Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2416 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2417 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2418 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2424 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2425 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2426 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pump Relay: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: All Technical Service Bulletins Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pump Relay: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 2432 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pump Relay: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 2438 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2439 Fuel Pump Relay: Locations FUEL PUMP RELAY Engine Compartment Wiring, LH Side The Fuel Pump Relay is located in the RH front of cowl, above blower motor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2440 C214, Fuel Pump Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2441 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2442 Fuel Pump Relay: Service and Repair Mounted To Right Side Engine Compartment REMOVAL 1. Verify that ignition switch is in the "OFF" position. 2. Disconnect wiring harness plug. 3. Remove fuel pump relay. INSTALLATION 1. Install new fuel pump relay. 2. Reconnect wiring harness plug to relay. 3. Verify correct operation to confirm repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Variable Induction Control Relay > Component Information > Locations Engine Wiring - RH Cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Diagrams C103, Ignition Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Diagrams > Page 2453 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: NOTE: It is not necessary to remove ignition distributor assembly from engine. 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. Tighten to 2 Nm (18 lb. in.) 4. Install pick up coil. 5. Install cap and rotor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 2461 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2464 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2465 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2466 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2467 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2468 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2469 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2470 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2471 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2472 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2473 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2474 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2475 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2476 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2477 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2478 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2479 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2480 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2481 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2482 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2483 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2484 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2485 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2486 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2487 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2488 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2489 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2490 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2491 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2492 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2493 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2494 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2495 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2496 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2497 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 2505 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 2508 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 2509 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2510 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2511 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2512 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View Manifold Pressure/Vacuum Sensor: Locations Assembly View MAP Sensor (Typical) The Manifold Absolute Pressure (MAP) Sensor is located on a bracket, mounted to the intake manifold on the passenger side next to the throttle body assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View > Page 2518 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2521 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2522 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2523 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2524 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2525 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2526 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2527 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2528 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2529 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2530 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2531 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2532 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2533 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2534 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2535 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2536 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2537 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2538 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2539 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2540 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2541 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2542 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2543 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2544 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2545 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2546 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2547 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2548 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2549 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2550 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2551 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2552 C104, MAP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2553 DTC 33 Circuit Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 2554 Manifold Pressure/Vacuum Sensor: Description and Operation Manifold Absolute Pressure (MAP) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. The computer sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the computer can determine the manifold absolute pressure. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum, which requires less fuel. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the computer to automatically adjust for different altitudes. The computer uses the MAP sensor to control fuel delivery and ignition timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2563 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2569 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Page 2579 Oxygen Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View Oxygen Sensor Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View > Page 2582 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2585 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2586 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2587 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2588 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2589 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2590 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2591 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2592 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2593 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2594 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2595 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2596 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2597 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2598 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2599 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2600 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2601 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2602 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2603 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2604 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2605 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2606 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2607 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2608 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2609 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2610 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2611 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2612 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2613 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2614 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2615 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2616 C108, Oxygen Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2617 Heated Oxygen Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2618 Oxygen Sensor: Description and Operation FUNCTION: The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION: The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315~C (600~F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Due to the electrolytic properties of the element the oxygen concentration differences between the reference air and the exhaust gases produce small voltages. OPERATION: A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES: An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE: The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/DIAGNOSTIC CHARTS/CODE 13. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2619 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION: ^ Connectors and wires ^ Housing and insulator for cracks/damage ^ Sensor tip for silicone contamination (white powdery coating) PERFORMANCE TEST: Checks working range and response (speed). 1. Warm engine 2. Install DVOM between sensor and ground (2 volt D.C. range) 3. "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). 4. Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. 5. Drive system lean: Create a vacuum leak from a source that is not an ECM input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE: After each test the O2 sensor should return to normal operating range within two to three seconds. 6. O2 Sensor should be replaced for failure to pass any of the tests above. NOTE: A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. 7. Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2620 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 2626 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2629 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2630 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2631 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2632 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2633 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2634 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2635 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2636 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2637 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2638 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2639 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2640 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2641 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2642 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2643 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2644 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2645 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2646 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2647 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2648 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2649 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2650 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2651 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2652 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2653 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2654 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2655 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2656 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2657 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2658 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2659 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2660 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2661 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 2662 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 2663 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 2664 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 2669 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 2670 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 2671 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 2672 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor (VSS) Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 2679 Transfer Case Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 2680 Vehicle Speed Sensor: Diagrams C240, I/P To VSS In-Line C212, VSS To I/P In-Line C394, Vehicle Speed Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation Vehicle Speed Sensor: Description and Operation Circuit Operation The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation > Page 2683 Vehicle Speed Sensor: Description and Operation Component Description Vehicle Speed Sensor (VSS) PURPOSE: The Vehicle Speed Sensor (VSS) provides information to the ECM for control of transmission Torque Converter Clutch (TCC), speedometer, odometer and cruise control. OPERATION: The VSS is a Permanent Magnet (PM) generator that produces a pulsing A/C voltage whenever vehicle speed exceeds about 3 mph (5 Kph). The A/C voltage level and the number of pulses increases with vehicle speed and is converted by the ECM to MPH (Kph). A VSS buffer is incorporated into the ECM for operating the instrument panel speedometer and odometer. LOCATION: Transaxle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Vehicle Speed Sensor: Initial Inspection and Diagnostic Overview Check condition of BRAKE Fuse. If fuse is blown, locate and repair source of overload. Replace fuse. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 2686 Vehicle Speed Sensor: Symptom Related Diagnostic Procedures Cruise Control Does Not Operate Properly (Part 1 Of 2) Cruise Control Does Not Operate Properly (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 2687 Speedometer And Odometers Do Not Operate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 2688 Vehicle Speed Sensor: Component Tests and General Diagnostics The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 2694 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 2695 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2696 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2697 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 2703 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2706 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2707 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2708 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2709 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2710 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2711 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2712 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2713 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2714 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2715 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2716 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2717 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2718 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2719 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2720 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2721 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2722 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2723 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2724 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2725 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2726 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2727 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2728 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2729 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2730 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2731 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2732 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2733 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2734 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2735 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2736 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2737 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2738 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 2739 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 2740 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 2741 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision > Page 2747 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 2750 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 2751 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 2752 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 2753 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 2754 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Diagnostic Connector - Fuel Pump: Locations Engine Component Wiring, LH Side Located RH front of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations > Page 2760 C122, Fuel Pump Prime Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 2765 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 2766 Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Auto D 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 2767 Idle Speed: Adjustments CONTROLLED IDLE SPEED CHECK NOTE: Before performing this check, there should be no codes displayed, idle air control system has been checked and the ignition timing is correct. 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, refer to DIAGNOSIS BY SYMPTOM/DIAGNOSIS AND TESTING PROCEDURES/ROUGH, UNSTABLE OR INCORRECT IDLE. MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Man. N 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 2777 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 2783 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark 4.3L (M/L) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications > Page 2803 Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Locations Distributor And Coil 4.3L Engine Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation Distributor: Service and Repair Removal & Installation Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2809 Distributor And Coil 4.3L Engine Distributor And Coil 5.0L And 5.7L (TBI) Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2810 Distributor And Coil - 7.4L Engine Removal: NOTE:Verify ignition switch is "OFF". 1. Disconnect wiring harness connectors at side of distributor. 2. Remove coil wire and sparkplug wires on either the left or right side of the distributor. 3. Remove distributor cap by the two screws and set to side: A. Bring engine to TDC on the compression stroke for the #1 cylinder and align timing marks to 0~ . B. Scribe a mark on the distributor housing in line with the rotor. C. Scribe a mark on the engine in line with the rotor. D. Note position of the distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. Installation: NOTE:To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Install distributor and gasket (if applicable). 2. Install hold-down clamp and tighten bolt: ^ Bolt on the 2.8R to 35 Nm (26 lb. ft.). ^ Bolt on the 4.3Z, 5.0H, 5.7K & 7.4N to 35 Nm (25 lb. ft.) 3. Install distributor cap. 4. Connect wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2811 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components Removal: 1. With distributor removed, disconnect wires at module terminals 2. Remove roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Remove gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Remove distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. Installation: 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 2812 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ............................................................... .045 inches Spark Plug Torque ............................................................................................................................... ..................................................... 15 Nm (11 lb. ft.) Spark Plug Type .................................................................................................................................. .............................................................. AC CR43TS NOTE: Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 2823 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 2824 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 2825 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > A/C Signal > Component Information > Description and Operation A/C Signal: Description and Operation A/C "ON" Signal Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: This signal indicates that the A/C control switch is turned "ON" and the pressure switch is closed. The control module uses this signal to adjust the idle speed for improved idle and engine performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 2838 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2841 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2842 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2843 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2844 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2845 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2846 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2847 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2848 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2849 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2850 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2851 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2852 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2853 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2854 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2855 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2856 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2857 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2858 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2859 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2860 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2861 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2862 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2863 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2864 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2865 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2866 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2867 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2868 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2869 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2870 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2871 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2872 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2873 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2874 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Reference Signal <--> [Cranking Signal] > Component Information > Description and Operation Reference Signal: Description and Operation Crank Signal NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The control module uses this signal to tell when the vehicle is in the STARTING mode. This information is used to allow enrichment and cancel diagnostics while engine is cranking. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Data Link Connector > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Data Link Connector > Component Information > Locations > Page 2881 C297, Data Link Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2886 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2887 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2888 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2889 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2890 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2891 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2892 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2893 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2894 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2895 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 2896 Powertrain Control Module Mounting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description Engine Control Module: Diagrams Connector Description PCM Connector Terminal End View (1 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2899 PCM Connector Terminal End View (2 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2900 PCM Connector Terminal End View (3 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2901 PCM Connector Terminal End View (4 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2902 Engine Control Module: Diagrams C204 (32-Pin Blue) C204, Powertrain Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2903 C204, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 2904 Engine Control Module: Diagrams C288 (32-Pin Red) C288, Powertrain Control Module C288, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2905 Engine Control Module: Description and Operation OPERATION: The control module is located in the passenger compartment and is the control center of the Computer Command Control system. The control module constantly receives information from various sensors. The computer performs the diagnostic functions of the system. The computer can recognize operational problems and alert the driver through the Malfunction Indicator Lamp (MIL) (Service Engine Soon light). The computer stores a trouble code which identifies the problem area to diagnose and repair. The computer is designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The computer has a learning ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected to clear trouble codes or for repair, the learning process has to begin all over again, and a change may be noticed in the driving performance of the vehicle. To reset the vehicles learning ability, make sure the engine is at operating temperature and operate the vehicle at part throttle, moderate acceleration, and idle conditions, until normal performance returns. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2906 Engine Control Module: Service and Repair Control Module Mounting CAUTION: [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, DO NOT touch the connector pins or soldered components on the circuit boards. NOTE: When replacing a production control module with a service controller, transfer the broadcast DTC and production control module part number to the controller label. DO NOT record information on the access cover. REMOVAL: 1. Disconnect the negative battery terminal. 2. Remove passenger kick panel. 3. Disconnect control module harness connectors. 4. Remove control module retainer and control module. 5. Remove brackets and modules if equipped.. 6. Remove access cover and PROM (MEM-CAL). INSTALLATION: 1. Install PROM (MEM-CAL) and access cover on to new control module. 2. Install mounting brackets and module(s) if equipped. 3. Connect control module harness connectors. 4. Install control module and retainer. 5. Install passenger kick panel. 6. Connect the negative battery terminal. 7. Perform functional check. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2910 C117, IAC Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2911 Idle Speed/Throttle Actuator - Electronic: Description and Operation Idle Air Control (IAC) System Idle Air Control Valve IAC System PURPOSE To control engine idle speed and prevent stalling due to changes in engine load. OPERATION All engine idle speeds are controlled by the control module through the Idle Air Control (IAC) valve mounted on the throttle body. The control module sends voltage pulses to the IAC motor windings causing the IAC motor shaft and pintle to move "IN" or "OUT" a given distance (number of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2912 steps) for each pulse (called counts). Inward movement of the pintle = Decreased RPM =Lower Counts. Outward movement of the pintle = Increased RPM = Higher Counts. This movement controls airflow around the throttle plate, which in turn, controls engine idle speed, either cold or hot. IAC valve pintle position counts can be seen using a Tech 1 scan tool. Zero (0) counts correspond to a fully closed passage, while 140 counts or more (depending on the application) corresponds to full flow. - Actual or "controlled" idle speed is obtained by the control module positioning the IAC valve pintle. Resulting idle speed is generated from the total idle air flow (IAC/passage + PCV + throttle valve + vacuum leaks). - Controlled idle speed is always specified for normal operating conditions. Normal operating condition is engine coolant temperature in operating range, the A/C is "OFF," manual transmission is in neutral or automatic transmission in drive with proper Park/Neutral Position (PNP) switch adjustment. A high or low engine coolant temperature, or A/C clutch engagement may signal the control module to change the IAC counts. - The minimum idle speed is set at the factory with a stop screw. This setting allows enough air flow by the throttle valves to cause the IAC valve pintle to be positioned a calibrated number of steps (counts) from the seat during normal controlled idle operation. The IAC counts will be higher than normal on an engine with less than 500 miles, or an engine operating at high altitude or an engine with an accessory load such as the alternator, A/C, power steering or hydra-boost brakes activated. Results of Incorrect Operation If the pintle is stuck open, the idle speed will remain high. If the pintle is stuck closed, the idle speed will be too low, and stalling may occur. If the pintle is stuck partially open, the idle speed will be higher than normal, and there will be no response to changes in engine load such as A/C ("ON") or transmission in ("Drive"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2913 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection Idle Air Control (IAC) System Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2914 Idle Air Control (IAC) System Check Circuit Description: The control module controls idle RPM with the IAC valve. To increase idle RPM, the control module moves the IAC valve away from its seat, allowing more air to pass by the throttle plate. To decrease RPM, it moves the IAC valve toward its seat, reducing air flow by the throttle plate. A Tech 1 Scan tool will read the control module commands to the IAC valve in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle). Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If NO change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 RPM and about 1500 RPM, the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 RPM), it may take Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2915 many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending the IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is OFF or does not flash red and green, check the circuits for faults beginning with poor terminal contacts. IAC VALVE RESET PROCEDURES: ^ With scan tool enter 10K mode. ^ Raise engine speed to 2000 RPM for 5 seconds. ^ Lower engine speed to idle. Diagnostic Aids: A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range IAC scan tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If Idle speed is above 800 RPM, locate and correct vacuum leak including crankcase ventilation system. Also, check for binding of the throttle blade or linkage. ^ System Too Lean (High Air/Fuel Ratio) - The idle speed may be too high or too low. Engine speed may vary up and down and disconnecting the IAC valve does not help. DTC 44 may be set scan O2s voltage will be less than 300 mV (.3 volts). Check for low regulated fuel pressure water in the fuel or a restricted injector. ^ System Too Rich (Low Air/Fuel Ratio) - The idle speed will be too low. Tech 1 scan tool IAC counts will usually be above 80. System is obviously rich and may exhibit black exhaust smoke. Tech 1 scan tool O2s voltage will be fixed above 800 mV (.8 volts). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated O2s scan voltage will be slow to respond. ^ Throttle Body - Remove IAC and inspect bore for foreign material. See DIAGNOSIS BY SYMPTOM. If intermittent poor driveability symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance, or replace IAC. ^ A/C Compressor or Relay Failure - Refer to A/C Diagnosis if circuit is shorted to ground. If the relay is faulty, idle problem may exist. See DIAGNOSIS BY SYMPTOM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2916 Idle Speed/Throttle Actuator - Electronic: Service and Repair NOTES: a. The Idle Air Control (IAC) valve is an electrical component and must not be soaked in any liquid cleaner or solvent. Otherwise damage could result. b. The IAC valve for this application is thread-mounted and has a dual taper, 10 mm diameter, pintle. Any replacement of the IAC valve must have the correct part number, with the appropriate pintle taper and diameter for proper seating of the valve in the throttle body. IAC Thread Mounted 10mm Pintle REMOVAL: 1. Disconnect electrical connector. 2. Remove IAC valve, use a 32 mm (1 1/4") wrench. 3. Remove IAC gasket and discard. 4. Clean old gasket material from surface of throttle body assembly to insure seal of new gasket. CLEAN: ^ Both original and replacement IAC valves have a special factory applied thread-locking compound applied to the screw threads. If the valve removed from throttle body is being reinstalled, DO NOT remove thread-locking that may remain on the threads. ^ Clean IAC valve seating surfaces on throttle body to assure proper seal of new gasket and IAC valve. Idle Air Control Valve Pintle Retraction (Manually) NOTES: a. If the IAC valve was removed during service, its operation may be tested electrically with the IAC/ISC Motor Tester (J-37027 or BT-8256K) or equivalent. Before installing a IAC valve, measure the distance between the tip of the valve pintle and the mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), the valve pintle must be retracted to prevent damage to the valve. This may be done electrically using an IAC/ISC Motor Tester or manually by exerting firm pressure, as shown in the illustration, with a slight side to side movement on valve pintle to retract it. b. No physical adjustment of the IAC valve assembly is required after installation. The IAC valve pintle is reset by turning the ignition ON for ten seconds and then OFF. The ECM then resets the pintle to the correct position. Proper idle regulation should result. INSTALLATION: 1. Install the IAC valve into throttle body with new gasket. NOTE: New IAC valves have been reset at the factory and should be installed in the throttle body in an "as is" condition, without any adjustment. 2. Tighten IAC valve assembly to 18.0 Nm (13.0 lb-ft). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Locations > Page 2917 3. Reconnect electrical connector to IAC valve. 4. "START" engine and allow it to reach operating temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 2925 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 2928 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 2929 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2930 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2931 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2932 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Malfunction Indicator Lamp > Component Information > Service and Repair Malfunction Indicator Lamp: Service and Repair The CHECK ENGINE LAMP will be illuminated when the ignition switch is placed in the "ON" position. When the engine is started, the lamp should turn "OFF". If the lamp remains "ON" for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Control Module. After diagnosis and repair, the ECM memory can be cleared of codes by removing the Control Module fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the "OFF" position. NOTE If battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. - It is a good idea to record preset radio stations before disconnecting the negative battery cable. This will allow the stations to be reset as to not inconvenience the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View Manifold Pressure/Vacuum Sensor: Locations Assembly View MAP Sensor (Typical) The Manifold Absolute Pressure (MAP) Sensor is located on a bracket, mounted to the intake manifold on the passenger side next to the throttle body assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View > Page 2941 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2944 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2945 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2946 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2947 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2948 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2949 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2950 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2951 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2952 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2953 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2954 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2955 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2956 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2957 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2958 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2959 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2960 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2961 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2962 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2963 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2964 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2965 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2966 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2967 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2968 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2969 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2970 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2971 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2972 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2973 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2974 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2975 C104, MAP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2976 DTC 33 Circuit Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 2977 Manifold Pressure/Vacuum Sensor: Description and Operation Manifold Absolute Pressure (MAP) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. The computer sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the computer can determine the manifold absolute pressure. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum, which requires less fuel. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the computer to automatically adjust for different altitudes. The computer uses the MAP sensor to control fuel delivery and ignition timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Memory Calibration Unit > Component Information > Technical Service Bulletins > PROM/MEMCAL - Identification Marks Memory Calibration Unit: Technical Service Bulletins PROM/MEMCAL - Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Memory Calibration Unit > Component Information > Technical Service Bulletins > PROM/MEMCAL - Identification Marks > Page 2982 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations Quad Driver: Locations Quad/Output drivers are hard wired onto the ECM/PCM/VCM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations > Page 2986 Quad Driver: Description and Operation Quad/Output Driver Module The Control Module in this vehicle controls most components with electronic switches which complete a ground circuit when turned on. When the switches are arranged in groups of 4, they can independently control up to 4 outputs and are called Quad Drivers. When the switches are arranged in groups of 7, they can independently control up to 7 outputs and are called Output Drivers. Not all outputs are always used. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations > Page 2987 Quad Driver: Testing and Inspection Little or no quad driver testing was supplied by the manufacturer. The engine module decides when to turn each switch of the driver "ON". Even though some models will set codes, in the end, if you want to check the driver itself, you'll need: 1. To use a scantool to command the suspected driver switch to energize (ground) the circuit, while checking with a test light, 2. To operate the vehicle in a way that should cause the suspected portion of the driver to switch "ON". On the up side, since the early 90's, most driver load circuits utilized circuit breakers. This protected most drivers and engine models from burning up when the circuit was overloaded. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations > Page 2988 Quad Driver: Service and Repair Quad/Output drivers are hard wired onto the ECM/PCM/VCM, and can't be serviced separately. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2997 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3003 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Page 3013 Oxygen Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View Oxygen Sensor Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View > Page 3016 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3019 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3020 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3021 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3022 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3023 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3024 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3025 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3026 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3027 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3028 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3029 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3030 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3031 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3032 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3033 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3034 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3035 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3036 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3037 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3038 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3039 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3040 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3041 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3042 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3043 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3044 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3045 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3046 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3047 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3048 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3049 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3050 C108, Oxygen Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3051 Heated Oxygen Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3052 Oxygen Sensor: Description and Operation FUNCTION: The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION: The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315~C (600~F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Due to the electrolytic properties of the element the oxygen concentration differences between the reference air and the exhaust gases produce small voltages. OPERATION: A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES: An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE: The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/DIAGNOSTIC CHARTS/CODE 13. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3053 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION: ^ Connectors and wires ^ Housing and insulator for cracks/damage ^ Sensor tip for silicone contamination (white powdery coating) PERFORMANCE TEST: Checks working range and response (speed). 1. Warm engine 2. Install DVOM between sensor and ground (2 volt D.C. range) 3. "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). 4. Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. 5. Drive system lean: Create a vacuum leak from a source that is not an ECM input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE: After each test the O2 sensor should return to normal operating range within two to three seconds. 6. O2 Sensor should be replaced for failure to pass any of the tests above. NOTE: A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. 7. Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3054 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3060 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3061 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3062 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3063 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3064 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3065 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3066 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3067 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3068 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3069 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3070 Powertrain Control Module Mounting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description Engine Control Module: Diagrams Connector Description PCM Connector Terminal End View (1 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 3073 PCM Connector Terminal End View (2 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 3074 PCM Connector Terminal End View (3 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 3075 PCM Connector Terminal End View (4 Of 4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 3076 Engine Control Module: Diagrams C204 (32-Pin Blue) C204, Powertrain Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 3077 C204, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Connector Description > Page 3078 Engine Control Module: Diagrams C288 (32-Pin Red) C288, Powertrain Control Module C288, Powertrain Control Module (Description) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3079 Engine Control Module: Description and Operation OPERATION: The control module is located in the passenger compartment and is the control center of the Computer Command Control system. The control module constantly receives information from various sensors. The computer performs the diagnostic functions of the system. The computer can recognize operational problems and alert the driver through the Malfunction Indicator Lamp (MIL) (Service Engine Soon light). The computer stores a trouble code which identifies the problem area to diagnose and repair. The computer is designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The computer has a learning ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected to clear trouble codes or for repair, the learning process has to begin all over again, and a change may be noticed in the driving performance of the vehicle. To reset the vehicles learning ability, make sure the engine is at operating temperature and operate the vehicle at part throttle, moderate acceleration, and idle conditions, until normal performance returns. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3080 Engine Control Module: Service and Repair Control Module Mounting CAUTION: [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, DO NOT touch the connector pins or soldered components on the circuit boards. NOTE: When replacing a production control module with a service controller, transfer the broadcast DTC and production control module part number to the controller label. DO NOT record information on the access cover. REMOVAL: 1. Disconnect the negative battery terminal. 2. Remove passenger kick panel. 3. Disconnect control module harness connectors. 4. Remove control module retainer and control module. 5. Remove brackets and modules if equipped.. 6. Remove access cover and PROM (MEM-CAL). INSTALLATION: 1. Install PROM (MEM-CAL) and access cover on to new control module. 2. Install mounting brackets and module(s) if equipped. 3. Connect control module harness connectors. 4. Install control module and retainer. 5. Install passenger kick panel. 6. Connect the negative battery terminal. 7. Perform functional check. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View Coolant Temperature Sensor/Switch (For Computer): Locations Assembly View Engine Coolant Temperature Sensor The Engine Coolant Temperature (ECT) Sensor is located on the intake manifold next to the thermostat housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Locations > Assembly View > Page 3090 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3093 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3094 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3095 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3096 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3097 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3098 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3099 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3100 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3101 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3102 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3103 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3104 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3105 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3106 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3107 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3108 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3109 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3110 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3111 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3112 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3113 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3114 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3115 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3116 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3117 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3118 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3119 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3120 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3121 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3122 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3123 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3124 C106, Engine Coolant Temperature Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3125 Temp Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 3126 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature (ECT) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Engine Coolant Temperature (ECT) sensor is a thermistor that is located in the engine coolant flow. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The control module sends a 5 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage the computer can determine engine coolant temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 3134 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 3137 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 3138 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3139 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3140 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3141 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View Manifold Pressure/Vacuum Sensor: Locations Assembly View MAP Sensor (Typical) The Manifold Absolute Pressure (MAP) Sensor is located on a bracket, mounted to the intake manifold on the passenger side next to the throttle body assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Locations > Assembly View > Page 3147 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3150 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3151 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3152 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3153 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3154 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3155 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3156 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3157 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3158 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3159 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3160 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3161 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3162 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3163 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3164 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3165 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3166 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3167 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3168 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3169 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3170 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3171 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3172 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3173 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3174 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3175 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3176 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3177 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3178 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3179 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3180 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3181 C104, MAP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3182 DTC 33 Circuit Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3183 Manifold Pressure/Vacuum Sensor: Description and Operation Manifold Absolute Pressure (MAP) Sensor Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. The computer sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the computer can determine the manifold absolute pressure. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum, which requires less fuel. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the computer to automatically adjust for different altitudes. The computer uses the MAP sensor to control fuel delivery and ignition timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3192 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3198 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Power Trunk / Liftgate Lock Actuator: All Technical Service Bulletins Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Page 3213 Oxygen Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View Oxygen Sensor Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Assembly View > Page 3216 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3219 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3220 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3221 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3222 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3223 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3224 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3225 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3226 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3227 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3228 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3229 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3230 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3231 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3232 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3233 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3234 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3235 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3236 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3237 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3238 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3239 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3240 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3241 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3242 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3243 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3244 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3245 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3246 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3247 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3248 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3249 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3250 C108, Oxygen Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3251 Heated Oxygen Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3252 Oxygen Sensor: Description and Operation FUNCTION: The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION: The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315~C (600~F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Due to the electrolytic properties of the element the oxygen concentration differences between the reference air and the exhaust gases produce small voltages. OPERATION: A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES: An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE: The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/DIAGNOSTIC CHARTS/CODE 13. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3253 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION: ^ Connectors and wires ^ Housing and insulator for cracks/damage ^ Sensor tip for silicone contamination (white powdery coating) PERFORMANCE TEST: Checks working range and response (speed). 1. Warm engine 2. Install DVOM between sensor and ground (2 volt D.C. range) 3. "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). 4. Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. 5. Drive system lean: Create a vacuum leak from a source that is not an ECM input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE: After each test the O2 sensor should return to normal operating range within two to three seconds. 6. O2 Sensor should be replaced for failure to pass any of the tests above. NOTE: A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. 7. Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3254 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 3260 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3263 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3264 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3265 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3266 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3267 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3268 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3269 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3270 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3271 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3272 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3273 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3274 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3275 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3276 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3277 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3278 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3279 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3280 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3281 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3282 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3283 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3284 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3285 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3286 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3287 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3288 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3289 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3290 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3291 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3292 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3293 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3294 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3295 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3296 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3297 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3298 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 3303 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 3304 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 3305 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 3306 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor (VSS) Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 3313 Transfer Case Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3314 Vehicle Speed Sensor: Diagrams C240, I/P To VSS In-Line C212, VSS To I/P In-Line C394, Vehicle Speed Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation Vehicle Speed Sensor: Description and Operation Circuit Operation The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation > Page 3317 Vehicle Speed Sensor: Description and Operation Component Description Vehicle Speed Sensor (VSS) PURPOSE: The Vehicle Speed Sensor (VSS) provides information to the ECM for control of transmission Torque Converter Clutch (TCC), speedometer, odometer and cruise control. OPERATION: The VSS is a Permanent Magnet (PM) generator that produces a pulsing A/C voltage whenever vehicle speed exceeds about 3 mph (5 Kph). The A/C voltage level and the number of pulses increases with vehicle speed and is converted by the ECM to MPH (Kph). A VSS buffer is incorporated into the ECM for operating the instrument panel speedometer and odometer. LOCATION: Transaxle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Vehicle Speed Sensor: Initial Inspection and Diagnostic Overview Check condition of BRAKE Fuse. If fuse is blown, locate and repair source of overload. Replace fuse. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 3320 Vehicle Speed Sensor: Symptom Related Diagnostic Procedures Cruise Control Does Not Operate Properly (Part 1 Of 2) Cruise Control Does Not Operate Properly (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 3321 Speedometer And Odometers Do Not Operate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 3322 Vehicle Speed Sensor: Component Tests and General Diagnostics The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 3328 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3331 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3332 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3333 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3334 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3335 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3336 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3337 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3338 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3339 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3340 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3341 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3342 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3343 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3344 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3345 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3346 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3347 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3348 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3349 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3350 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3351 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3352 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3353 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3354 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3355 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3356 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3357 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3358 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3359 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3360 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3361 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3362 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3363 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3364 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3365 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3366 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 3371 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 3372 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 3373 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 3374 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor (VSS) Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 3381 Transfer Case Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3382 Vehicle Speed Sensor: Diagrams C240, I/P To VSS In-Line C212, VSS To I/P In-Line C394, Vehicle Speed Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation Vehicle Speed Sensor: Description and Operation Circuit Operation The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Description and Operation > Circuit Operation > Page 3385 Vehicle Speed Sensor: Description and Operation Component Description Vehicle Speed Sensor (VSS) PURPOSE: The Vehicle Speed Sensor (VSS) provides information to the ECM for control of transmission Torque Converter Clutch (TCC), speedometer, odometer and cruise control. OPERATION: The VSS is a Permanent Magnet (PM) generator that produces a pulsing A/C voltage whenever vehicle speed exceeds about 3 mph (5 Kph). The A/C voltage level and the number of pulses increases with vehicle speed and is converted by the ECM to MPH (Kph). A VSS buffer is incorporated into the ECM for operating the instrument panel speedometer and odometer. LOCATION: Transaxle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Vehicle Speed Sensor: Initial Inspection and Diagnostic Overview Check condition of BRAKE Fuse. If fuse is blown, locate and repair source of overload. Replace fuse. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 3388 Vehicle Speed Sensor: Symptom Related Diagnostic Procedures Cruise Control Does Not Operate Properly (Part 1 Of 2) Cruise Control Does Not Operate Properly (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 3389 Speedometer And Odometers Do Not Operate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 3390 Vehicle Speed Sensor: Component Tests and General Diagnostics The speedometer receives a vehicle speed signal from the Vehicle Speed Sensor Buffer. The Vehicle Speed Sensor Buffer receives an AC voltage signal from the transmission mounted Vehicle Speed Sensor (VSS). The VSS generates a signal that indicates the speed of the vehicle. The Signal is processed by the solid-state Vehicle Speed Sensor Buffer to supply inputs to the Powertrain Control Module (PCM), the Cruise Control Module and the Speedometer. The VSS is mounted in the transmission. A toothed rotor rotates near a coil, producing voltage pulses in the coil. The rotor that is attached to the transmission turns four times faster than a standard speedometer cable. The coil near the rotor generates 40 pulses per revolution. The frequency of the AC voltage coming from this coil depends on the vehicle speed. As the speed increases, so does the number of voltage pulses per second. The Vehicle Speed Sensor Buffer takes the voltage pulses from the sensor and uses them to close three solid-state output switches. Each output terminal is switched to ground at a rate that is proportional to the speed of the vehicle. The Speedometer is switched by the primary rate of the VSS. The PCM and the Cruise Control use a lower frequency. Their input switches are operated by a circuit that divides the sensor frequency by two. Different Vehicle Speed Sensor Buffers are used to match the vehicle final drive ratio to the components. WARNING: THE FOLLOWING TEST REQUIRES THAT YOU FREE-ROLL THE REAR WHEELS OF THE VEHICLE ON THE HOIST. BE SURE THE WHEELS ARE FREE OF OBSTRUCTIONS AND THAT YOU AND OTHERS STAY CLEAR OF THE WHEELS AT ALL TIMES. FAILURE TO DO SO MAY RESULT IN INJURY OR DEATH. DO NOT BRING WHEEL SPEED ABOVE 70 MPH. ON AN ALL-WHEEL DRIVE L VANS, BOTH FRONT AND REAR WHEELS MUST BE FREE TO ROTATE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations Vehicle Speed Sensor Signal Buffer: Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations > Page 3394 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations > Page 3395 Vehicle Speed Sensor Signal Buffer: Diagrams C267, Vehicle Speed Sensor Buffer C231, Vehicle Speed Sensor Buffer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations Exhaust System With Catalytic Converter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3400 Catalytic Converter: Description and Operation Catalytic Converters CAUTION: Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3401 NOTE: When jacking or lifting vehicle from frame side rails, be certain lift pads DO NOT contact catalytic converter or damage to converter may result. The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, entering the atmosphere. The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains unchanged, ready to repeat the process. This device sometimes requires the use of heat shields, due to its high operating temperatures. The heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs, are: single bed monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three-way (reduction) catalyst. The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The three-way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three-way catalysts. A fill pipe restrictor is used on catalytic converter equipped vehicles, to prevent the larger service station pump nozzle, used for leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalysts, rendering them ineffective, the use of unleaded fuels is mandatory in catalytic converter equipped vehicles. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3402 Catalytic Converter: Testing and Inspection RESTRICTED EXHAUST TEST Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedure(s) may be used for diagnosis: Exhaust System Check CHECK AT A.I.R. PIPE - Remove the rubber hose at the exhaust manifold A.I.R. pipe check valve and remove check valve. - Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device. - Insert the nipple into the exhaust manifold A.I.R. pipe. CHECK AT 02 SENSOR - Carefully remove O2 sensor. - Install Exhaust Backpressure Tester in place of 02 sensor. - After completing the diagnosis described below, be sure to coat threads of 02 sensor with anti-seize compound prior to re-installation. DIAGNOSIS - With the engine idling at normal operating temperature, transaxle in park or neutral, observe the exhaust system backpressure reading on the gauge. The reading should not exceed .5 psi or 3.4 kPa. Increase engine speed to 3000 rpm and observe gauge. The reading should not exceed .75 psi or 5 kPa. - If the backpressure exceeds the given specifications, a restricted exhaust system is indicated. - Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure. - If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced. WITH VACUUM GAUGE Engine at normal operating temperature: Connect a vacuum gauge to any convenient vacuum port on intake manifold. - Run engine at 1000 rpm and record vacuum reading. - Increase rpm slowly to 2500 rpm. Note vacuum reading at a steady 2500 rpm - If vacuum at 2500 rpm decreases more than 3" Hg, from reading at 1000 rpm, the exhaust system should be inspected for restrictions - Disconnect exhaust pipe from engine and repeat Step 2 & 3. If vacuum still drops more than 3" Hg, with exhaust disconnected, check for exhaust manifold restriction and valve timing. THERMAL TEST Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3403 Use a pyrometer to measure the temperature difference between the inlet and outlet. A warm and properly working catalytic converter will show about 100 degrees hotter at the outlet. NOTE:A fuel system that is running rich will not produce a catalyst and will indicate little or no temperature variation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Canister Purge Solenoid > Component Information > Testing and Inspection Canister Purge Solenoid: Testing and Inspection Canister Purge Control Circuit Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Canister Purge Solenoid > Component Information > Testing and Inspection > Page 3408 Cannister Purge Solenoid Check Circuit Description: 12 volts is applied to CKT 439 at terminal "A" when the ignition key is turned "ON". As the engine coolant temperature rises during engine operation (45~C - 113~F) or when short term fuel trim count is > 122, the control module will then ground CKT 428 at terminal "B". The purge solenoid will then open the vapor canister to purge the fuel, and direct it to the intake manifold for normal combustion when it is needed. Test Description: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Canister Purge Solenoid > Component Information > Testing and Inspection > Page 3409 Numbers below refer to circled numbers on the diagnostic chart. 1. Checks to see if a vacuum source is present, along with certain conditions before the purge solenoid is commanded "ON". Also shows a change of vacuum as purge solenoid is being cycled. 2. Checks for power to the solenoid, the ground circuit, the connections at the purge solenoid and the solenoid itself. 3. Checks for open or grounded CKT 439. 4. Checks for open CKT 428 or faulty control module. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Canister Purge Solenoid > Component Information > Testing and Inspection > Page 3410 Canister Purge Solenoid: Service and Repair Canister Purge Solenoid Mounting Removal: 1. Disconnect the negative battery terminal. 2. Disconnect the electrical connector and hoses from the solenoid. 3. Remove the solenoid from the mounting bracket by pulling away from the bracket. Installation: 1. Slide the solenoid into the bracket. 2. Connect the electrical connector and hoses to the solenoid. 3. Connect the negative battery terminal. 4. Check to insure proper operation of the solenoid valve. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Canister Filter > Component Information > Service and Repair Evaporative Canister Filter: Service and Repair NOTE: NOT ALL EVAPORATIVE EMISSION CONTROL CANISTERS HAVE A SERVICEABLE FILTER. At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, 1. Remove all hoses from the top of the canister and mark. Remove the canister. 2. Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. 3. Squeeze the new element under retainer bar, where used, and position it evenly around the entire bottom of the canister. Tuck the edges under the lip of canister. 4. Reinstall the canister to its original position on the vehicle, following normal service procedures. 5. Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Emission Control Canister > Component Information > Service and Repair Evaporative Emission Control Canister: Service and Repair Removal - Remove hoses from canister. Mark hoses for installation of new canister. - Remove screw from bracket and canister. Installation - Install new canister and secure to bracket with screw. - Connect hoses to canister making sure hoses are connected to the correct ports. - Check operation of new canister. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Control Solenoid > Component Information > Diagrams C118, EGR Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Control Solenoid > Component Information > Diagrams > Page 3421 EGR Control Solenoid: Description and Operation EGR System OPERATION: To regulate EGR flow an ECM controlled solenoid is used in the vacuum line. This is a normally closed solenoid vacuum valve which is opened when the ECM completes the ground. The ECM will energize the EGR solenoid (EGR ON) when the engine is warm and above idle. There is little EGR flow at wide open throttle due to lack of engine vacuum. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Electronic Vacuum Regulator Solenoid > Component Information > Description and Operation EGR Electronic Vacuum Regulator Solenoid: Description and Operation Exhaust Gas Recirculation (EGR) System Circuit Diagram PURPOSE The exhaust gas recirculation (EGR) system is used to reduce oxides of nitrogen (NOx) emissions. The atmosphere is made up of mostly Nitrogen, with a smaller percentage of oxygen, and a mixture of other gases. Oxygen and Nitrogen do not normally combine except at very high temperatures and pressures, conditions which are present in the combustion chamber especially during hard acceleration. When the engine is under load, the EGR valve admits a small amount of exhaust gas into the intake manifold to mix with the air/fuel charge. The exhaust gas is essentially inert (contains no fuel or oxidizer) and reduces peak combustion temperatures and pressures by absorbing some of the heat of combustion without participating in the actual burn. Greater amounts of exhaust gas are metered in as engine speed and load are increased. The linear EGR valve is designed to accurately supply regulated amounts of exhaust gas to the intake manifold, independent of manifold vacuum. OPERATION The linear EGR valve gets battery power when the ignition is turned "ON" and becomes energized when the control module completes the circuit to ground. When a solenoid is energized, the armature, with attached shaft and swivel pintle, is lifted and the orifice is opened. The linear EGR valve uses a potentiometer to measure the amount of valve opening. The PCM utilizes Pulse Width Modulation (PWM) to control EGR operation. When the necessary conditions are met for EGR operation the PCM closes the ground switch to the EGR valve, the EGR pintle position sensor relays the current EGR orifice opening to the PCM. The PCM then varies the PWM until the actual orifice opening matches the desired orifice opening. The PCM uses the information from the the following sensors to control the flow: 1. Coolant temperature (CTS) 2. Throttle Position Sensor (TPS) 3. Manifold Absolute Pressure (MAP) 4. Barometric (BARO) Pressure 5. PRNDL Switch position 6. Pintle Position Sensor CONSTRUCTION The pintle that closes the EGR orifice is attached directly to the solenoid shaft with. The effects of EGR leakage on idle quality are reduced because the shaft and seals are exposed to the exhaust pressure instead of manifold vacuum. The shaft is sealed from the exhaust chamber by a floating seal held in place by the seal spring. This spring also holds the upper seal of the armature cavity in the solenoid. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Linear EGR - Installation Procedure Revision EGR Valve: Technical Service Bulletins Linear EGR - Installation Procedure Revision FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 51-65-32 DATE: May, 1995 SUBJECT: Section 6E3, 9, 9C, 9A - Driveability and Emissions - Revised Linear EGR installation Procedure MODELS: 1992-95 Chevrolet and GMC Truck M/L Vans 1992-95 Chevrolet and GMC Truck S/T Models 1993-95 Chevrolet and GMC Truck C/K Models 1994-95 Chevrolet and GMC Truck G Vans 1994-95 Chevrolet and GMC Truck P3, P/G Chassis 1992-93 Oldsmobile Bravada with 4.3L, 7.4L Engines (VINs W, N - RPOs L35, L19) and (VIN Z - RPO LB4 - with California Emissions) This service bulletin revises the Linear EGR installation Procedure, in the following service manuals: 1992-93 Oldsmobile Bravada Service Manual, page 6E3-C7-6. 1992-93 Light Duty Truck, Fuel and Emissions Service Manual, pages 9-19 and 90-6. 1994-95 S/T Driveability Emissions and Electrical Diagnosis Service Manual and the 1994 S/T Truck Supplement with RPO CTF, page 9A-8. 1994-95 C/K, M/L, G Van and P/G and P3 Chassis Driveability Emissions and Electrical Diagnosis Service Manuals, page 9A-6. The revised procedure is as follows: Install or Connect 1. EGR valve and new gasket. 2. Valve to flange bolts. Tighten Tighten bolts in two steps. a. The first step to 10 Nm (89 lb.in.). b. The second step to 25 Nm (18 lb.ft.). 3. Electrical connector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3429 EGR Valve: Specifications Valve To Intake Manifold Torque Valve To Intake Manifold Torque EGR Valve to Intake Manifold 17 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3430 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3431 EGR Valve: Description and Operation The EGR system routes exhaust gases from the exhaust manifold to the intake manifold at specified engine operating conditions. The EGR valve is opened by vacuum and exhaust backpressure, letting exhaust gas flow into the intake manifold. The exhaust gas then moves with the air/fuel mixture into the combustion chamber. Since there is less air/fuel mixture to burn in the combustion chamber during EGR operation, the temperature is reduced enough to limit NOx formation. If too much exhaust gas enters, combustion will NOT occur. Because of this, very little exhaust gas is allowed to pass through the valve, especially at idle. The valve should only open when the engine is at operating temperature and above idle speed. Variations in vacuum and exhaust backpressure, control the amount of exhaust gas recirculation. Negative Backpressure EGR Valve The negative backpressure EGR valve has the bleed valve spring below the diaphragm, and the valve is normally in the closed position. The negative backpressure EGR valve varies the amount of exhaust gas flow into the manifold depending on manifold vacuum and variations in exhaust backpressure. The diaphragm on the valve has an internal air bleed hole which is held closed by a small spring when there is no exhaust backpressure. Engine vacuum opens the EGR valve against the pressure of a large spring. When manifold vacuum combines with negative exhaust backpressure, the vacuum bleed hole opens and the EGR valve closes. This valve will open if vacuum is applied and the engine is not operating. EGR Valve Identification The negative backpressure EGR valve can be identified by the letter "N" stamped on the top side of the valve immediately following the part number. See illustration. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3432 EGR Valve: Testing and Inspection WARNING: Appropriate eye protection should be worn when cleaning the EGR system to prevent injury to eyes. CAUTION: DO NOT wash the EGR valve in solvents or degreaser as permanent damage to the valve diaphragm may result. Also, sand blasting of the valve is not recommended since this can affect the operation of the valve. 1. With a wire wheel, buff the exhaust deposits from the mounting surface and around the valve. 2. Look for exhaust deposits in the valve outlet. Remove deposit build up with a screwdriver. 3. Clean the mounting surfaces of the intake manifold and valve assembly. 4. Install valve assembly using new gasket. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Service and Repair > EGR Intake Manifold Cleaning EGR Valve: Service and Repair EGR Intake Manifold Cleaning CAUTION: When cleaning intake manifold EGR passages, care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve or from being ingested into the engine, as damage to system or engine may occur. 1. Remove throttle body. 2. Disconnect vacuum hose or electrical connector from EGR valve, then remove EGR valve to manifold retaining bolts and valve. 3. Remove deposits from EGR ports by hand using a suitable drill bit and screwdriver. 4. Brush small deposits down EGR port into passages, then using compressed air, blow ports clean. Solvents should not be used to clean EGR valve or passages, since damage to system may result. 5. Install EGR valve, using new gasket. 6. Install throttle body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Service and Repair > EGR Intake Manifold Cleaning > Page 3435 EGR Valve: Service and Repair EGR Valve Cleaning WARNING: Appropriate eye protection should be worn when cleaning the EGR system to prevent injury to eyes. CAUTION: DO NOT wash the EGR valve in solvents or degreaser as permanent damage to the valve diaphragm may result. Also, sand blasting of the valve is not recommended since this can affect the operation of the valve. 1. With a wire wheel, buff the exhaust deposits from the mounting surface and around the valve. 2. Look for exhaust deposits in the valve outlet. Remove deposit build up with a screwdriver. 3. Clean the mounting surfaces of the intake manifold and valve assembly. 4. Install valve assembly using new gasket. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Fillpipe Restrictor > Component Information > Description and Operation Fillpipe Restrictor: Description and Operation Fuel Door And Restrictor (Typical) PURPOSE To prevent refueling with leaded fuel, the fuel filter neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Positive Crankcase Ventilation > Crankcase Filter > Component Information > Service and Repair Crankcase Filter: Service and Repair The PCV system should be checked every 15,000 miles and also during regular engine tune-ups. If the PCV system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the PCV valve or air cleaner is replaced. When a periodic inspection indicates the PCV is not functioning properly, it should be serviced by replacement only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Positive Crankcase Ventilation > Positive Crankcase Ventilation Valve > Component Information > Service and Repair Positive Crankcase Ventilation Valve: Service and Repair The PCV system should be checked every 15,000 miles and also during regular engine tune-ups. If the PCV system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the PCV valve or air cleaner is replaced. When a periodic inspection indicates the PCV is not functioning properly, it should be serviced by replacement only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Thermostatic Air Cleaner > Component Information > Description and Operation Thermostatic Air Cleaner: Description and Operation Air Cleaner With Heated Air Intake System Thermac Operation DESCRIPTION A heated intake air system is used for good driveability under varying climatic conditions. Having a uniform inlet air temperature improves fuel vaporization. OPERATION The THERMAC system regulates in incoming air temperature without the use of vacuum. The air regulating damper is controlled by means of a self contained, wax pellet actuated assembly mounted in the air cleaner. When incoming air is cold, the wax material sealed in the actuator is in a solid phase and the damper closes off the cold air inlet. This causes all incoming air to be heated by the exhaust manifold. As the incoming air warms, the wax material expands changing to a liquid phase which forces out a piston to reposition the damper allowing a cold and hot air mix or all cold air to enter the engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Thermostatic Air Cleaner > Component Information > Description and Operation > Page 3449 Thermostatic Air Cleaner: Testing and Inspection SYSTEM CHECK Results of Incorrect THERMAC Operation May Cause hesitation during warm up, check for: ^ Heat stove tube disconnected. ^ Damper door does not move (stuck closed). ^ Missing air cleaner to TBI unit seal. ^ Missing air cleaner cover seal or loose cover. ^ Loose air cleaner. Lack of power, sluggish, pinging or spongy, on a hot engine check for: ^ Damper door does not open to outside air. Air Cleaner Functional Check 1. Remove air cleaner assembly and cool to below 40 degrees FAHRENHEIT. The damper should be closed to outside air. 2. Check for presence and condition of air cleaner to throttle body gasket. 3. Reinstall air cleaner and be sure heat stove tube is connected at air cleaner snorkel and exhaust manifold. 4. Start engine. Watch damper door in air cleaner snorkel. As air cleaner warms up, damper door should open slowly to outside air. 5. If air cleaner fails to operate as described, be sure calibrated spring is properly installed and damper is not binding. If OK, replace wax pellet actuator assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Thermostatic Air Cleaner > Component Information > Description and Operation > Page 3450 Thermostatic Air Cleaner: Service and Repair Wax Pellet Installation REMOVAL: 1. Vehicle air cleaner assembly. 2. If application has a plastic heat tube elbow, use an 1/8" drill bit to drill out the two rivets that secure it to the heat tube and remove elbow. If application does NOT have an elbow, skip this step. 3. Use an 1/8" drill bit to drill out the rivets that secure the wax pellet carrier assembly. 4. Remove the blow down spring. 5. Remove the wax pellet carrier assembly. INSPECTION: Examine the spring clip on the hot air damper. Replace if necessary. INSTALLATION: 1. Install a new blow down spring. 2. Reinstall plastic heat tube elbow in the correct orientation, using two pop rivets. 3. Reinstall air cleaner assembly on vehicle. 4. Check thermostatic air cleaner to ensure proper operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Diagnostic Connector - Fuel Pump: Locations Engine Component Wiring, LH Side Located RH front of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations > Page 3456 C122, Fuel Pump Prime Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 3464 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Page 3465 Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Auto D 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Page 3466 Idle Speed: Adjustments CONTROLLED IDLE SPEED CHECK NOTE: Before performing this check, there should be no codes displayed, idle air control system has been checked and the ignition timing is correct. 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, refer to DIAGNOSIS BY SYMPTOM/DIAGNOSIS AND TESTING PROCEDURES/ROUGH, UNSTABLE OR INCORRECT IDLE. MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Man. N 538 5-30 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable for this engine. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Accelerator Pedal > Component Information > Service and Repair Accelerator Pedal: Service and Repair Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: - The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Accelerator Pedal > Component Information > Service and Repair > Page 3470 Control Cable And Linkage ACCELERATOR CONTROL CABLE When performing service on the accelerator control cable, observe the following: - The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud or release cable from pulley. - Retainer locking tangs from support bracket. - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel. INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 3480 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 3486 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Diagnostic Connector - Fuel Pump > Component Information > Locations Diagnostic Connector - Fuel Pump: Locations Engine Component Wiring, LH Side Located RH front of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Diagnostic Connector - Fuel Pump > Component Information > Locations > Page 3490 C122, Fuel Pump Prime Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fillpipe Restrictor > Component Information > Description and Operation Fillpipe Restrictor: Description and Operation Fuel Door And Restrictor (Typical) PURPOSE To prevent refueling with leaded fuel, the fuel filter neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > Customer Interest: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage Fuel: Customer Interest Fuel System - Factors That Affect Economy/Mileage Number: 93-96-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 306502 ASE No.: A1, A8 Subject: FACTORS THAT AFFECT FUEL ECONOMY Model and Year: ALL YEARS ALL MODELS BACKGROUND INFORMATION: EPA fuel economy estimates are posted on the fuel economy label of all new vehicles. The only intended use of these values is for comparison among the different vehicles. Fuel economy estimates are generated from data taken during a laboratory test using pre-production prototype vehicles under extremely controlled conditions using a professional driver, with the vehicle operating on an instrument similar to a treadmill. The comparisons of current vehicle fuel economy to the EPA fuel economy estimates is a misuse of the information and should be discouraged. The EPA GAS MILEAGE GUIDE, available at each dealership, points out that the actual mileage when driving a vehicle may differ considerably from the estimated mileage. The guide also describes how vehicles are tested under identical conditions to insure the results can be compared with confidence. The EPA GAS MILEAGE GUIDE also points out that city fuel economy estimate simulates a 7.5 mile, stop-and-go trip with an average speed of 20 mph. The trip takes 23 minutes and has 18 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. Two kinds of engine starts are used - the cold start, which is similar to starting a car in the morning after it has been parked all night - and the hot start, similar to restarting a vehicle after it has been warmed up, driven and stopped for a short time. The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10 mile trip and averages 48 mph. The test is run from a hot start and has little idling time and no stops. The EPA GAS MILEAGE GUIDE explains that the actual test results are adjusted downward to arrive at the estimates used in the booklet and on the labels. City estimates are lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. The guide also points out that traveling at higher speeds lowers fuel economy and traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent. FACTORS THAT AFFECT FUEL ECONOMY: Axle Ratio Numerically lower axle ratios generally produce better highway fuel economy. The exception to this is if the engine is "working" exceptionally hard, (heavy vehicle loads pulling a trailer, small engine in a large vehicle ... ). In these cases a numerically higher axle may provide better fuel economy. Numerically higher axle ratios will also tend to provide more fuel economy in congested city traffic and stop and go conditions. Brakes Brake drag (even a minimal amount undetectable by coasting), can have a significant negative impact on fuel economy. Pull upward on the brake pedal to assure that the stoplight switch and cruise switch at the brake pedal are full and properly adjusted. A "click" sound when the pedal is pulled upward indicates that the switch was improperly adjusted. This causes the front brake pads to lightly rub the rotors, causing a fuel economy loss, without generating excessive heat or brake pad wear. Driving Habits Frequent short trips (less than 5 miles), especially in cooler ambient temperatures (less than 65 degrees), will necessitate fuel enrichment on start-ups, especially after "soaks" with the engine off for approximately a half hour or more. Frequent accelerator pedal movement while driving will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (TCC) also disengages, contributing to fuel economy losses. Prolonged idle periods reduce fuel economy especially in cold ambients when vehicle is allowed to "Warm up". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > Customer Interest: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage > Page 3502 Fuels Oxygenated fuels, with methanol and/or ethanol blended into the gasoline have lower energy and thus reduce fuel economy. Typically there is about a 1 MPG penalty for a vehicle which gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "KS" Knock Sensor system activity. This will result in a net decrease in spark advance and thus poorer fuel economy. Using fuel of a higher octane than the vehicle was calibrated for WILL NOT increase fuel economy. Variations in how much fuel is added to the fuel tank during re-fueling can greatly affect calculated fuel economy. These effects decrease as the distance traveled and the number of tank fillups increase. Green Engine New vehicles have not yet had an opportunity for the engine to break in, (rings to seat ... ). A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected. Parasitic Loads Air conditioning and/or electrical loads, (headlights, heated backglass ... ) also result in lower fuel economy, (typically less than 1 MPG difference, each 10 AMPs takes approximately .4 MPG). Road Conditions Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual unperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy. Suspension Vehicle suspension misalignment can cause poor fuel economy. Check all four tires for abnormal and/or premature tire wear. New tires, tire rotation, and/or front end alignment may be required to correct fuel economy. Tires Performance tires and/or tires with larger "contact areas," (like 60 series aspect ratio), can cause as much as 3 MPG lower fuel economy when compared to hard "thin" tires. Find out if the tire size currently on the car is the same as original equipment. Replacement tires tailor than original equipment tires cause the odometer to read LESS THAN actual distance traveled. This will result in lower calculated fuel economy than actual fuel economy. Tire Pressure Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride. Transmission On 4-Speed automatics, it is possible to drive the vehicle in 3rd gear rather than "overdrive" and not perceive it. Typically this condition occurs when the shift indicator, or the shift linkage/detent is misadjusted. Misadjusted shift linkage can also result in improper signals to the ECM, which can result in less spark advance, and results in a drop in fuel economy. Driving a vehicle in 3rd gear rather than overdrive at highway speeds typically results in a 3 to 5 MPG penalty. Torque Converter Clutch operation is essential for good fuel economy. A non-locking torque converter typically results in a 1 to 2 MPG penalty at highway speeds. Vehicle Weight Each 125 lbs. of additional weight results in a .3 MPG loss of fuel economy. Thus, additional passengers, luggage ... will decrease fuel economy. Vehicle Wind Resistance More wind "DRAG" means less fuel economy. Thus, hang-on luggage carders, cat toppers, open windows and/or open trunk... mean less fuel economy. (See "Driving Habits"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) Fuel: All Technical Service Bulletins Fuel System - TOP TIER Detergent Gasoline (Canada) INFORMATION Bulletin No.: 05-06-04-022G Date: October 27, 2010 Subject: TOP TIER Detergent Gasoline Information and Available Brands (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - Canada ONLY Models: 2011 and Prior GM Passenger Cars and Trucks (Canada Only) Supercede: This bulletin is being revised to update the model years and include an additional gasoline brand as a TOP TIER source. Please discard Corporate Bulletin Number 05-06-04-022F (Section 06 - Engine/Propulsion System). In the U.S., refer to the latest version of Corporate Bulletin Number 04-06-04-047I. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by the Canadian General Standards Board (CGSB). Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. Intake valve: 16,093 km (10,000 mi) with TOP TIER Detergent Gasoline Intake valve: 16,093 km (10,000 mi) with Minimum Additive recommended by the CGSB Top Tier Fuel Availability Chevron was the first to offer TOP TIER Detergent Gasoline in Canada. Shell became the first national gasoline retailer to offer TOP TIER Detergent Gasoline across Canada. Petro-Canada began offering TOP TIER Detergent Gasoline nationally as of October 1, 2006. Sunoco began offering TOP TIER Detergent Gasoline in March of 2007. Esso began offering TOP TIER Detergent Gasoline in May of 2010. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3508 Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards The following gasoline brands meet the TOP TIER Detergent Gasoline Standards in all octane grades : Chevron Canada (markets in British Columbia and western Alberta) - Shell Canada (nationally) - Petro-Canada (nationally) - Sunoco-Canada (Ontario) - Esso-Canada (nationally) What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency and no metallic additives. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent recommendations of Canadian standards and does not contain metallic additives, which can damage vehicle emission control components. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began in the U.S. and Canada on May 3, 2004. Some fuel marketers have already joined and introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: BMW, General Motors, Honda, Toyota, Volkswagen and Audi. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. In the U.S., government regulations require that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In Canada, gasoline standards recommend adherence to U.S. detergency requirements but do not require it. In fact, many brands of gasoline in Canada do not contain any detergent additive. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required or recommended, and no metallic additives are allowed. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency and the intentional addition of metallic additives is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Clean engines help provide optimal fuel economy and engine performance, and also provide reduced emissions. Also, the use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Who should use TOP TIER Detergent Gasoline? All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. More information on TOP TIER Detergent Gasoline can be found at this website, http://www.toptiergas.com/. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3509 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel System - 'TOP TIER' Detergent Gasoline Information INFORMATION Bulletin No.: 04-06-04-047I Date: August 17, 2009 Subject: TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only Models: 2010 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only) 2003-2010 HUMMER H2 (U.S. Only) 2006-2010 HUMMER H3 (U.S. Only) 2005-2009 Saab 9-7X (U.S. Only) Supercede: This bulletin is being revised to add model years and additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047H (Section 06 Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022F. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline. Intake valve: - 10,000 miles with TOP TIER Detergent Gasoline Intake valve: - 10,000 miles with Legal Minimum additive Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards As of August 1, 2009, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards: - Chevron - Chevron-Canada - QuikTrip - Conoco Phillips 66 - 76 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information > Page 3514 - Shell - Shell-Canada - Entec Stations located in the greater Montgomery, Alabama area. - MFA Oil Company located throughout Missouri. - Kwik Trip, Inc. in Minnesota and Wisconsin and Kwik Star convenience stores in Iowa. The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky. Aloha Petroleum - Tri-Par Oil Company - Turkey Hill Minit Markets - Texaco - Petro-Canada - Sunoco-Canada - Road Ranger located in Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio and Wisconsin What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent requirements imposed by the EPA. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began on May 3, 2004 and many fuel marketers have joined the program and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Where Can I find the Latest Information on TOP TIER Fuel and Retailers? On the web, please visit www.toptiergas.com for additional information and updated retailer lists. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: Audi, BMW, General Motors, Honda, Toyota and Volkswagen. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 04-06-00-047 > Jun > 04 > Fuel - Top Tier Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel - Top Tier Detergent Gasoline Information Bulletin No.: 04-06-00-047 Date: June 24, 2004 ADVANCED SERVICE INFORMATION Subject: Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) Models: 2005 and Prior All General Motors Passenger Cars and Trucks (U.S. Only) A new class of gasoline, called Top Tier Detergent Gasoline, will be appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. A description of the concept and benefits of Top Tier is provided in the following question and answer section. What is Top Tier Detergent Gasoline? Top Tier Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA. Who developed Top Tier Detergent Gasoline standards? Top Tier Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota. Why was Top Tier Detergent Gasoline developed? Top Tier Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet Top Tier Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, Top Tier was developed to give fuel marketers the opportunity to differentiate their product. Why did the four automotive companies join together to develop Top Tier? All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of Top Tier Detergent Gasoline? Top Tier Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of Top Tier Detergent Gasoline will help reduce deposit related concerns. Who should use Top Tier Detergent Gasoline? All vehicles will benefit from using Top Tier Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from use of Top Tier Detergent Gasoline. Where can Top Tier Detergent Gasoline be purchased? The Top Tier program began on May 3, 2004. Some fuel marketers have already joined and are making plans to introduce Top Tier Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, look for the "Top Tier" designation at the gas pump. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 570102 > Jun > 95 > Fuel Reformulated/Oxygenated Gasolines Fuel: All Technical Service Bulletins Fuel - Reformulated/Oxygenated Gasolines FILE IN SECTION: 0 - General Information BULLETIN NO.: 57-01-02 DATE: June, 1995 SUBJECT: Reformulated Gasoline (RFG), Oxygenated Gasoline and California Phase 2 RFG MODELS: 1995 and Prior Passenger Cars and Trucks General Motors customers will be potentially exposed to a variety of different fuel types. Besides the conventional gasoline available, new types such as Reformulated Gasoline (RFG), oxygenated gasoline, and starting in 1996, California Phase 2 RFG. Reformulated Gasoline (RFG) is blended to burn more cleanly and not to evaporate as readily. RFG must contain a minimum of 2 percent oxygen, which is usually achieved with ethanol or EPA-approved ethers such as methyl tertiary-butyl ether (MTBE). This type of fuel is required by the Clean Air Act in the nine worst ozone non-attainment areas of the country, and may also be required in other areas designated ozone non-attainment, at the option of the states. RFG is intended to produce approximately 15 percent less pollution than conventional gasoline. Using RFG should reduce the total health risk to the public by reducing exposure to ozone and air toxins. General Motors supports the use of RFG as a cost effective means of providing air quality benefits. Oxygenated gasolines are prevalent in the wintertime for Carbon Monoxide (CO) non-attainment areas. These fuels contain oxygen components similar to RFG. Approximately 50 percent of the fuel sold in the U.S. in the wintertime contains an oxygenate component. Vehicle fuel economy may be slightly reduced, if at all, by the use of gasoline containing oxygenates. Fuel economy is most affected by engine and vehicle type, driving habits, weather conditions, and vehicle maintenance. Properly blended RFG, oxygenated gasoline, and California Phase 2 RFG will have no adverse effect on vehicle performance or to the durability of engine and fuel system components. In fact, the General Motors Owner's Manual fuel statements have consistently permitted the use of properly blended fuels containing up to 10 percent ethanol (since 1980) and up to 15 percent methyl tertiary-butyl ether (MTBE) for current and all past model year vehicles. These statements continue to be valid. The use of oxygenate-containing fuels will not invalidate the GM vehicle warranty. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage Fuel: All Technical Service Bulletins Fuel System - Factors That Affect Economy/Mileage Number: 93-96-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 306502 ASE No.: A1, A8 Subject: FACTORS THAT AFFECT FUEL ECONOMY Model and Year: ALL YEARS ALL MODELS BACKGROUND INFORMATION: EPA fuel economy estimates are posted on the fuel economy label of all new vehicles. The only intended use of these values is for comparison among the different vehicles. Fuel economy estimates are generated from data taken during a laboratory test using pre-production prototype vehicles under extremely controlled conditions using a professional driver, with the vehicle operating on an instrument similar to a treadmill. The comparisons of current vehicle fuel economy to the EPA fuel economy estimates is a misuse of the information and should be discouraged. The EPA GAS MILEAGE GUIDE, available at each dealership, points out that the actual mileage when driving a vehicle may differ considerably from the estimated mileage. The guide also describes how vehicles are tested under identical conditions to insure the results can be compared with confidence. The EPA GAS MILEAGE GUIDE also points out that city fuel economy estimate simulates a 7.5 mile, stop-and-go trip with an average speed of 20 mph. The trip takes 23 minutes and has 18 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. Two kinds of engine starts are used - the cold start, which is similar to starting a car in the morning after it has been parked all night - and the hot start, similar to restarting a vehicle after it has been warmed up, driven and stopped for a short time. The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10 mile trip and averages 48 mph. The test is run from a hot start and has little idling time and no stops. The EPA GAS MILEAGE GUIDE explains that the actual test results are adjusted downward to arrive at the estimates used in the booklet and on the labels. City estimates are lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. The guide also points out that traveling at higher speeds lowers fuel economy and traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent. FACTORS THAT AFFECT FUEL ECONOMY: Axle Ratio Numerically lower axle ratios generally produce better highway fuel economy. The exception to this is if the engine is "working" exceptionally hard, (heavy vehicle loads pulling a trailer, small engine in a large vehicle ... ). In these cases a numerically higher axle may provide better fuel economy. Numerically higher axle ratios will also tend to provide more fuel economy in congested city traffic and stop and go conditions. Brakes Brake drag (even a minimal amount undetectable by coasting), can have a significant negative impact on fuel economy. Pull upward on the brake pedal to assure that the stoplight switch and cruise switch at the brake pedal are full and properly adjusted. A "click" sound when the pedal is pulled upward indicates that the switch was improperly adjusted. This causes the front brake pads to lightly rub the rotors, causing a fuel economy loss, without generating excessive heat or brake pad wear. Driving Habits Frequent short trips (less than 5 miles), especially in cooler ambient temperatures (less than 65 degrees), will necessitate fuel enrichment on start-ups, especially after "soaks" with the engine off for approximately a half hour or more. Frequent accelerator pedal movement while driving will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (TCC) also disengages, contributing to fuel economy losses. Prolonged idle periods reduce fuel economy especially in cold ambients when vehicle is allowed to "Warm up". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage > Page 3527 Fuels Oxygenated fuels, with methanol and/or ethanol blended into the gasoline have lower energy and thus reduce fuel economy. Typically there is about a 1 MPG penalty for a vehicle which gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "KS" Knock Sensor system activity. This will result in a net decrease in spark advance and thus poorer fuel economy. Using fuel of a higher octane than the vehicle was calibrated for WILL NOT increase fuel economy. Variations in how much fuel is added to the fuel tank during re-fueling can greatly affect calculated fuel economy. These effects decrease as the distance traveled and the number of tank fillups increase. Green Engine New vehicles have not yet had an opportunity for the engine to break in, (rings to seat ... ). A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected. Parasitic Loads Air conditioning and/or electrical loads, (headlights, heated backglass ... ) also result in lower fuel economy, (typically less than 1 MPG difference, each 10 AMPs takes approximately .4 MPG). Road Conditions Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual unperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy. Suspension Vehicle suspension misalignment can cause poor fuel economy. Check all four tires for abnormal and/or premature tire wear. New tires, tire rotation, and/or front end alignment may be required to correct fuel economy. Tires Performance tires and/or tires with larger "contact areas," (like 60 series aspect ratio), can cause as much as 3 MPG lower fuel economy when compared to hard "thin" tires. Find out if the tire size currently on the car is the same as original equipment. Replacement tires tailor than original equipment tires cause the odometer to read LESS THAN actual distance traveled. This will result in lower calculated fuel economy than actual fuel economy. Tire Pressure Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride. Transmission On 4-Speed automatics, it is possible to drive the vehicle in 3rd gear rather than "overdrive" and not perceive it. Typically this condition occurs when the shift indicator, or the shift linkage/detent is misadjusted. Misadjusted shift linkage can also result in improper signals to the ECM, which can result in less spark advance, and results in a drop in fuel economy. Driving a vehicle in 3rd gear rather than overdrive at highway speeds typically results in a 3 to 5 MPG penalty. Torque Converter Clutch operation is essential for good fuel economy. A non-locking torque converter typically results in a 1 to 2 MPG penalty at highway speeds. Vehicle Weight Each 125 lbs. of additional weight results in a .3 MPG loss of fuel economy. Thus, additional passengers, luggage ... will decrease fuel economy. Vehicle Wind Resistance More wind "DRAG" means less fuel economy. Thus, hang-on luggage carders, cat toppers, open windows and/or open trunk... mean less fuel economy. (See "Driving Habits"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) Fuel: All Technical Service Bulletins Fuel System - TOP TIER Detergent Gasoline (Canada) INFORMATION Bulletin No.: 05-06-04-022G Date: October 27, 2010 Subject: TOP TIER Detergent Gasoline Information and Available Brands (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - Canada ONLY Models: 2011 and Prior GM Passenger Cars and Trucks (Canada Only) Supercede: This bulletin is being revised to update the model years and include an additional gasoline brand as a TOP TIER source. Please discard Corporate Bulletin Number 05-06-04-022F (Section 06 - Engine/Propulsion System). In the U.S., refer to the latest version of Corporate Bulletin Number 04-06-04-047I. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by the Canadian General Standards Board (CGSB). Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. Intake valve: 16,093 km (10,000 mi) with TOP TIER Detergent Gasoline Intake valve: 16,093 km (10,000 mi) with Minimum Additive recommended by the CGSB Top Tier Fuel Availability Chevron was the first to offer TOP TIER Detergent Gasoline in Canada. Shell became the first national gasoline retailer to offer TOP TIER Detergent Gasoline across Canada. Petro-Canada began offering TOP TIER Detergent Gasoline nationally as of October 1, 2006. Sunoco began offering TOP TIER Detergent Gasoline in March of 2007. Esso began offering TOP TIER Detergent Gasoline in May of 2010. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3533 Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards The following gasoline brands meet the TOP TIER Detergent Gasoline Standards in all octane grades : Chevron Canada (markets in British Columbia and western Alberta) - Shell Canada (nationally) - Petro-Canada (nationally) - Sunoco-Canada (Ontario) - Esso-Canada (nationally) What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency and no metallic additives. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent recommendations of Canadian standards and does not contain metallic additives, which can damage vehicle emission control components. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began in the U.S. and Canada on May 3, 2004. Some fuel marketers have already joined and introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: BMW, General Motors, Honda, Toyota, Volkswagen and Audi. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. In the U.S., government regulations require that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In Canada, gasoline standards recommend adherence to U.S. detergency requirements but do not require it. In fact, many brands of gasoline in Canada do not contain any detergent additive. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required or recommended, and no metallic additives are allowed. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency and the intentional addition of metallic additives is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Clean engines help provide optimal fuel economy and engine performance, and also provide reduced emissions. Also, the use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Who should use TOP TIER Detergent Gasoline? All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. More information on TOP TIER Detergent Gasoline can be found at this website, http://www.toptiergas.com/. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3534 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel System - 'TOP TIER' Detergent Gasoline Information INFORMATION Bulletin No.: 04-06-04-047I Date: August 17, 2009 Subject: TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only Models: 2010 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only) 2003-2010 HUMMER H2 (U.S. Only) 2006-2010 HUMMER H3 (U.S. Only) 2005-2009 Saab 9-7X (U.S. Only) Supercede: This bulletin is being revised to add model years and additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047H (Section 06 Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022F. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline. Intake valve: - 10,000 miles with TOP TIER Detergent Gasoline Intake valve: - 10,000 miles with Legal Minimum additive Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards As of August 1, 2009, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards: - Chevron - Chevron-Canada - QuikTrip - Conoco Phillips 66 - 76 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information > Page 3539 - Shell - Shell-Canada - Entec Stations located in the greater Montgomery, Alabama area. - MFA Oil Company located throughout Missouri. - Kwik Trip, Inc. in Minnesota and Wisconsin and Kwik Star convenience stores in Iowa. The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky. Aloha Petroleum - Tri-Par Oil Company - Turkey Hill Minit Markets - Texaco - Petro-Canada - Sunoco-Canada - Road Ranger located in Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio and Wisconsin What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent requirements imposed by the EPA. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began on May 3, 2004 and many fuel marketers have joined the program and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Where Can I find the Latest Information on TOP TIER Fuel and Retailers? On the web, please visit www.toptiergas.com for additional information and updated retailer lists. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: Audi, BMW, General Motors, Honda, Toyota and Volkswagen. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 04-06-00-047 > Jun > 04 > Fuel - Top Tier Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel - Top Tier Detergent Gasoline Information Bulletin No.: 04-06-00-047 Date: June 24, 2004 ADVANCED SERVICE INFORMATION Subject: Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) Models: 2005 and Prior All General Motors Passenger Cars and Trucks (U.S. Only) A new class of gasoline, called Top Tier Detergent Gasoline, will be appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. A description of the concept and benefits of Top Tier is provided in the following question and answer section. What is Top Tier Detergent Gasoline? Top Tier Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA. Who developed Top Tier Detergent Gasoline standards? Top Tier Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota. Why was Top Tier Detergent Gasoline developed? Top Tier Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet Top Tier Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, Top Tier was developed to give fuel marketers the opportunity to differentiate their product. Why did the four automotive companies join together to develop Top Tier? All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of Top Tier Detergent Gasoline? Top Tier Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of Top Tier Detergent Gasoline will help reduce deposit related concerns. Who should use Top Tier Detergent Gasoline? All vehicles will benefit from using Top Tier Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from use of Top Tier Detergent Gasoline. Where can Top Tier Detergent Gasoline be purchased? The Top Tier program began on May 3, 2004. Some fuel marketers have already joined and are making plans to introduce Top Tier Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, look for the "Top Tier" designation at the gas pump. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 570102 > Jun > 95 > Fuel - Reformulated/Oxygenated Gasolines Fuel: All Technical Service Bulletins Fuel - Reformulated/Oxygenated Gasolines FILE IN SECTION: 0 - General Information BULLETIN NO.: 57-01-02 DATE: June, 1995 SUBJECT: Reformulated Gasoline (RFG), Oxygenated Gasoline and California Phase 2 RFG MODELS: 1995 and Prior Passenger Cars and Trucks General Motors customers will be potentially exposed to a variety of different fuel types. Besides the conventional gasoline available, new types such as Reformulated Gasoline (RFG), oxygenated gasoline, and starting in 1996, California Phase 2 RFG. Reformulated Gasoline (RFG) is blended to burn more cleanly and not to evaporate as readily. RFG must contain a minimum of 2 percent oxygen, which is usually achieved with ethanol or EPA-approved ethers such as methyl tertiary-butyl ether (MTBE). This type of fuel is required by the Clean Air Act in the nine worst ozone non-attainment areas of the country, and may also be required in other areas designated ozone non-attainment, at the option of the states. RFG is intended to produce approximately 15 percent less pollution than conventional gasoline. Using RFG should reduce the total health risk to the public by reducing exposure to ozone and air toxins. General Motors supports the use of RFG as a cost effective means of providing air quality benefits. Oxygenated gasolines are prevalent in the wintertime for Carbon Monoxide (CO) non-attainment areas. These fuels contain oxygen components similar to RFG. Approximately 50 percent of the fuel sold in the U.S. in the wintertime contains an oxygenate component. Vehicle fuel economy may be slightly reduced, if at all, by the use of gasoline containing oxygenates. Fuel economy is most affected by engine and vehicle type, driving habits, weather conditions, and vehicle maintenance. Properly blended RFG, oxygenated gasoline, and California Phase 2 RFG will have no adverse effect on vehicle performance or to the durability of engine and fuel system components. In fact, the General Motors Owner's Manual fuel statements have consistently permitted the use of properly blended fuels containing up to 10 percent ethanol (since 1980) and up to 15 percent methyl tertiary-butyl ether (MTBE) for current and all past model year vehicles. These statements continue to be valid. The use of oxygenate-containing fuels will not invalidate the GM vehicle warranty. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Filler Cap > Component Information > Locations Fuel Filler Neck Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Filler Cap > Component Information > Locations > Page 3551 Fuel Filler Cap: Service and Repair If a fuel tank filler cap requires replacement, use only a cap with the same features. Failure to use the correct cap can result in a malfunctioning of the evaporative system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair A constant bleed feature in the pressure regulator relieves pressure when the when the engine is turned "OFF". 1. Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. 2. Loosen the fuel filler cap to relieve tank vapor pressure. 3. The internal constant bleed feature of TBI relieves fuel pump system pressure when the engine is turned "OFF". Therefore no further pressure relief procedure is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Fuel System - Fuel Injector Maintenance Cleaning Fuel Injector: Technical Service Bulletins Fuel System - Fuel Injector Maintenance Cleaning Bulletin No.: 04-06-04-051B Date: January 04, 2006 INFORMATION Subject: Maintenance Cleaning of Fuel Injectors Models: 2006 and Prior All General Motors Passenger Cars and Trucks 2003-2006 HUMMER H2 2006 HUMMER H3 Supercede: This bulletin is being revised to add models and model years and update the name and part number of GM Fuel System Treatment. Please discard Corporate Bulletin Number 04-06-04-051A (Section 06 - Engine/Propulsion System). General Motors is aware that some companies are marketing tools, equipment and programs to support fuel injector cleaning as a preventative maintenance procedure. General Motors does not endorse, support or acknowledge the need for fuel injector cleaning as a preventative maintenance procedure. Fuel injector cleaning is approved only when performed as directed by a published GM driveability or DTC diagnostic service procedure. Due to variation in fuel quality in different areas of the country, the only preventative maintenance currently endorsed by GM regarding its gasoline engine fuel systems is the addition of GM Fuel System Treatment PLUS, P/N 88861011 (for U.S. ACDelco(R), use P/N 88861013) (in Canada, P/N 88861012), added to a tank of fuel at each oil change. Refer to Corporate Bulletin Number 03-06-04-030A for proper cleaning instructions. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Fuel System - Fuel Injector Maintenance Cleaning > Page 3560 Fuel Injector: Technical Service Bulletins Tools - Introduction Of The Fuel Injector Tester NO.: 93-I-39 DATE: June, 1993 GROUP: 6 CORP. NO.: 316501R SUBJECT: INFORMATION ON THE INTRODUCTION OF THE FUEL INJECTOR TESTER TOOL J - 39021 This bulletin is being revised to add information about the coil test and a list of driveability problems. In February, 1993, Kent-Moore shipped a new Fuel Injector Tester, tool J-39021, as part of the Essential Tool Program. This tool has the capability of performing injector balance and coil tests on all GM and many non-GM fuel injection systems. The injector balance test is one familiar to most technicians where fuel pressure drop is measured as an injector is energized for a set period of time. This fuel pressure drop is compared to that of the other injectors in the vehicle or a published standard. The injector coil test is a new test whereby the injector's resistance is measured during normal gperation by feeding a fixed current through the injector and measuring the voltage across the injector. Injector coil failures are more accurately detected using this method than by simply measuring the injectors resistance with an ohmmeter. Refer to the instructions included with the tool for testing procedures. This tool, and the injector coil test specifically, were developed to detect deterioration of injector coils due to the introduction of injector cleaners and fuel blends containing high levels of alcohol. Alcohol and water carried by the alcohol may attack and corrode injector coils resulting in a change in coil resistance and one or more of the following driveability symptoms: ^ rough idle ^ engine miss/surge ^ stall after start/hard start ^ fails emission test ^ poor fuel economy ^ exhaust odor The injector coil test procedure also requires the use of the Digital Voltmeter, J-39200, to measure the voltage across the injector during the test. The Fuel Injector Tester, J-39021, supplies one of three fixed current values throughout the duration of the test. Selection of the supply current value (0.5, 2.5, or 4.0 amps) is based on the injector's specified resistance. When the push-to-start-test button is pressed, the tool energizes the injector coil for five seconds. The condition of the injector coil (pass/fail) is determined by the voltage reading displayed on the voltmeter while the injector is energized. Instructions and specifications for most GM fuel injectors are included with the tool. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3561 Fuel Injector: Locations Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3562 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3563 Fuel Injector: Diagrams C119, Injector A C120, Injector B Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3564 Fuel Injector: Testing and Inspection PROCEDURE: - Connect fuel pressure gauge. - Block off (pinch) return line. - Power up fuel pump (engine "OFF") by applying 12 volts to fuel pump "test" terminal. - Verify fuel pressure is stable and remains constant. - Visually inspect injectors for evidence of fuel dribbling. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3565 Fuel Injector: Service and Repair CAUTION: a. Each fuel injector is serviced as a complete assembly only. b. Use care in removing the fuel injectors to prevent damage to the electrical connector terminals, the injector filter, and the fuel nozzle. The fuel injector is serviced as a complete assembly only. Also, since the injectors are electrical components, they should not be immersed in any type of liquid solvent or cleaner as damage could occur. Fuel Injector Removal REMOVAL: 1. Disconnect electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up.) 2. Remove fuel meter cover assembly, refer to FUEL METER COVER ASSEMBLY. 3. With fuel meter cover gasket in place to prevent damage to casting, use a screwdriver and fulcrum to carefully lift out each injector. 4. Remove lower (small) O-rings from nozzle of injectors and discard. 5. Remove fuel meter cover gasket and discard. 6. Remove upper (large) O-rings and steel backup washers from top of fuel injector cavity and discard. INSPECTION: - Fuel injector filter for evidence of dirt and contamination. If present, check for presence of dirt in fuel lines and fuel tank. If dirt is present refer to MAINTENANCE PROCEDURES/FUEL SYSTEM CLEANING. Fuel Injector Part Number Location Be sure to replace the injector with an identical part. Different injectors with different flow rates will fit this unit, but are calibrated for different flow rates. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3566 Fuel Injector Installation INSTALLATION: 1. Lubricate new lower (small) O-rings with automatic transmission fluid and push on nozzle end of injector until it presses against injector fuel filter. 2. Install steel injector back up washer in counterbore of fuel meter body. 3. Lubricate new upper (large) O-rings with automatic transmission fluid and install directly over the back up washer. Be sure the O-ring is seated properly and is flush with top of fuel meter body surface. NOTE: Backup washers and O-rings must be installed before injectors, or improper seating of large O-rings could cause fuel to leak. 4. Install injector, aligning raised lug on each injector base with notch in fuel meter body cavity. Push down on injector until it is fully seated in the fuel meter body. (Electrical terminals of the injector should be parallel with throttle shaft). 5. Install fuel meter cover gasket. 6. Install fuel meter cover. 7. Reconnect electrical connectors to fuel injectors. 8. With engine OFF and ignition ON, check for fuel leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > Customer Interest: > 66-63-09 > Apr > 97 > Engine Hard Start or No Start Fuel Pressure Pulsation Damper: Customer Interest Engine - Hard Start or No Start File In Section: 6E - Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks It the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description QTY 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Labor Op Description Labor Time J 5590 Pump, Fuel R&R; Use Published Labor Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pressure Pulsation Damper: > 66-63-09 > Apr > 97 > Engine - Hard Start or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start or No Start File In Section: 6E - Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks It the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description QTY 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Labor Op Description Labor Time J 5590 Pump, Fuel R&R; Use Published Labor Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pressure Pulsation Damper: > 666309 > Apr > 97 > Engine - Hard Start Or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start Or No Start File In Section: 6E Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description Qty 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. use: Labor Op Description Labor Time Use Published Labor J 5590 Pump, Fuel R&R; Operation Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pressure Pulsation Damper: > 666309 > Apr > 97 > Engine - Hard Start Or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start Or No Start File In Section: 6E Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description Qty 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. use: Labor Op Description Labor Time Use Published Labor J 5590 Pump, Fuel R&R; Operation Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Diagnostic Connector - Fuel Pump: Locations Engine Component Wiring, LH Side Located RH front of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations > Page 3594 C122, Fuel Pump Prime Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Control Unit > Component Information > Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3606 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3607 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3608 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine Will Not Start Readily Upon Cranking > Page 3614 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine Will Not Start Readily Upon Cranking > Page 3615 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine Will Not Start Readily Upon Cranking > Page 3616 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pump Relay: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt Retractor: All Technical Service Bulletins Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3627 Fuel Pump Relay: Locations FUEL PUMP RELAY Engine Compartment Wiring, LH Side The Fuel Pump Relay is located in the RH front of cowl, above blower motor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3628 C214, Fuel Pump Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3629 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3630 Fuel Pump Relay: Service and Repair Mounted To Right Side Engine Compartment REMOVAL 1. Verify that ignition switch is in the "OFF" position. 2. Disconnect wiring harness plug. 3. Remove fuel pump relay. INSTALLATION 1. Install new fuel pump relay. 2. Reconnect wiring harness plug to relay. 3. Verify correct operation to confirm repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Return Line > Component Information > Service and Repair Fuel Return Line: Service and Repair NOTES: a. When replacing fuel feed and return pipes, always replace them with original equipment or parts that meet GM specifications for those parts. The replacement pipe must have the same type fittings as the original pipes to ensure the integrity of the connection. b. Do not use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124M specification or its equivalent is capable of meeting all pressure and vibration characteristics necessary to ensure the durability standard required. Many of the feed and return pipes use screw couplings with O-rings. Any time these fittings are loosened to service or to replace components, ensure that: - A back-up wrench is used to loosen and tighten fittings. - Check all O-rings at these locations (if applicable) for cuts or any damage and replace as necessary. - Use correct torque when tightening these fittings. - Inspect all pipes for kinks, leaks or dents. - Pipes must be properly secured to the frame to prevent chafing. A minimum of 6 mm (1/4 inch) clearance must be maintained around a pipe to prevent contact or chafing. - Fuel feed and return pipes are secured to the underbody with clamps and screw assemblies. - Follow the same routing as the original pipe. - Fuel pipes must not contact the fuel tank or underbody at any point. FUEL AND VAPOR PIPE REPAIR: When it is impractical to replace an entire fuel line to repair localized damage, use the following procedure: - When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Flouroelastomer" on the hose. The inside diameter of the hose must match the outside pipe diameter. - Do not use rubber hose within 100 mm (4 inches) of any part of the exhaust system, or within 254 mm (10 inches) of the catalytic converter. - In repairable areas, cut a piece of hose 100 mm (4 inches) longer than the portion of line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 254 mm (10 inches). - Follow the same routing as the original pipe. - Cut the ends of the pipe, remaining on the car, square with a tubing cutter. Using the first step of a double flaring tool, form a bead on the end of each pipe section. If the pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also. - Use a screw type hose clamp NO. #2494772, or equivalent. Slide the clamps onto the pipe and push hoses 51 mm (2 inches) onto each portion of the fuel pipe. Tighten the clamps on each side of the repair. - Pipes must be properly secured to the frame to prevent chafing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Supply Line > Component Information > Service and Repair Fuel Supply Line: Service and Repair NOTES: a. When replacing fuel feed and return pipes, always replace them with original equipment or parts that meet GM specifications for those parts. The replacement pipe must have the same type fittings as the original pipes to ensure the integrity of the connection. b. Do not use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124M specification or its equivalent is capable of meeting all pressure and vibration characteristics necessary to ensure the durability standard required. Many of the feed and return pipes use screw couplings with O-rings. Any time these fittings are loosened to service or to replace components, ensure that: - A back-up wrench is used to loosen and tighten fittings. - Check all O-rings at these locations (if applicable) for cuts or any damage and replace as necessary. - Use correct torque when tightening these fittings. - Inspect all pipes for kinks, leaks or dents. - Pipes must be properly secured to the frame to prevent chafing. A minimum of 6 mm (1/4 inch) clearance must be maintained around a pipe to prevent contact or chafing. - Fuel feed and return pipes are secured to the underbody with clamps and screw assemblies. - Follow the same routing as the original pipe. - Fuel pipes must not contact the fuel tank or underbody at any point. FUEL AND VAPOR PIPE REPAIR: When it is impractical to replace an entire fuel line to repair localized damage, use the following procedure: - When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Flouroelastomer" on the hose. The inside diameter of the hose must match the outside pipe diameter. - Do not use rubber hose within 100 mm (4 inches) of any part of the exhaust system, or within 254 mm (10 inches) of the catalytic converter. - In repairable areas, cut a piece of hose 100 mm (4 inches) longer than the portion of line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 254 mm (10 inches). - Follow the same routing as the original pipe. - Cut the ends of the pipe, remaining on the car, square with a tubing cutter. Using the first step of a double flaring tool, form a bead on the end of each pipe section. If the pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also. - Use a screw type hose clamp NO. #2494772, or equivalent. Slide the clamps onto the pipe and push hoses 51 mm (2 inches) onto each portion of the fuel pipe. Tighten the clamps on each side of the repair. - Pipes must be properly secured to the frame to prevent chafing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Filler Hose > Component Information > Locations Fuel Filler Neck Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Gauge Sender > Component Information > Locations Fuel Pump And Sender Assembly (Typical) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Gauge Sender > Component Information > Locations > Page 3644 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull fuel pump up into attaching hose while pulling outward from the bottom support. ^ Do not damage rubber insulator or strainer. INSPECTION: 1. Inspect fuel pump attaching hose for signs of deterioration. 2. Inspect rubber sound insulation at bottom of pump for deterioration. INSTALLATION: 1. Install pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). 3. Install cam lock assembly. Turn cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect negative battery cable. 6. START vehicle and check for fuel leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Tank Pressure Release Valve > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank Unit > Component Information > Diagrams Fuel Tank Unit: Diagrams C395, Fuel Sender Unit C395, Fuel Sender Unit Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3654 C117, IAC Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3655 Idle Speed/Throttle Actuator - Electronic: Description and Operation Idle Air Control (IAC) System Idle Air Control Valve IAC System PURPOSE To control engine idle speed and prevent stalling due to changes in engine load. OPERATION All engine idle speeds are controlled by the control module through the Idle Air Control (IAC) valve mounted on the throttle body. The control module sends voltage pulses to the IAC motor windings causing the IAC motor shaft and pintle to move "IN" or "OUT" a given distance (number of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3656 steps) for each pulse (called counts). Inward movement of the pintle = Decreased RPM =Lower Counts. Outward movement of the pintle = Increased RPM = Higher Counts. This movement controls airflow around the throttle plate, which in turn, controls engine idle speed, either cold or hot. IAC valve pintle position counts can be seen using a Tech 1 scan tool. Zero (0) counts correspond to a fully closed passage, while 140 counts or more (depending on the application) corresponds to full flow. - Actual or "controlled" idle speed is obtained by the control module positioning the IAC valve pintle. Resulting idle speed is generated from the total idle air flow (IAC/passage + PCV + throttle valve + vacuum leaks). - Controlled idle speed is always specified for normal operating conditions. Normal operating condition is engine coolant temperature in operating range, the A/C is "OFF," manual transmission is in neutral or automatic transmission in drive with proper Park/Neutral Position (PNP) switch adjustment. A high or low engine coolant temperature, or A/C clutch engagement may signal the control module to change the IAC counts. - The minimum idle speed is set at the factory with a stop screw. This setting allows enough air flow by the throttle valves to cause the IAC valve pintle to be positioned a calibrated number of steps (counts) from the seat during normal controlled idle operation. The IAC counts will be higher than normal on an engine with less than 500 miles, or an engine operating at high altitude or an engine with an accessory load such as the alternator, A/C, power steering or hydra-boost brakes activated. Results of Incorrect Operation If the pintle is stuck open, the idle speed will remain high. If the pintle is stuck closed, the idle speed will be too low, and stalling may occur. If the pintle is stuck partially open, the idle speed will be higher than normal, and there will be no response to changes in engine load such as A/C ("ON") or transmission in ("Drive"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3657 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection Idle Air Control (IAC) System Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3658 Idle Air Control (IAC) System Check Circuit Description: The control module controls idle RPM with the IAC valve. To increase idle RPM, the control module moves the IAC valve away from its seat, allowing more air to pass by the throttle plate. To decrease RPM, it moves the IAC valve toward its seat, reducing air flow by the throttle plate. A Tech 1 Scan tool will read the control module commands to the IAC valve in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle). Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If NO change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 RPM and about 1500 RPM, the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 RPM), it may take Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3659 many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending the IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is OFF or does not flash red and green, check the circuits for faults beginning with poor terminal contacts. IAC VALVE RESET PROCEDURES: ^ With scan tool enter 10K mode. ^ Raise engine speed to 2000 RPM for 5 seconds. ^ Lower engine speed to idle. Diagnostic Aids: A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range IAC scan tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If Idle speed is above 800 RPM, locate and correct vacuum leak including crankcase ventilation system. Also, check for binding of the throttle blade or linkage. ^ System Too Lean (High Air/Fuel Ratio) - The idle speed may be too high or too low. Engine speed may vary up and down and disconnecting the IAC valve does not help. DTC 44 may be set scan O2s voltage will be less than 300 mV (.3 volts). Check for low regulated fuel pressure water in the fuel or a restricted injector. ^ System Too Rich (Low Air/Fuel Ratio) - The idle speed will be too low. Tech 1 scan tool IAC counts will usually be above 80. System is obviously rich and may exhibit black exhaust smoke. Tech 1 scan tool O2s voltage will be fixed above 800 mV (.8 volts). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated O2s scan voltage will be slow to respond. ^ Throttle Body - Remove IAC and inspect bore for foreign material. See DIAGNOSIS BY SYMPTOM. If intermittent poor driveability symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance, or replace IAC. ^ A/C Compressor or Relay Failure - Refer to A/C Diagnosis if circuit is shorted to ground. If the relay is faulty, idle problem may exist. See DIAGNOSIS BY SYMPTOM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3660 Idle Speed/Throttle Actuator - Electronic: Service and Repair NOTES: a. The Idle Air Control (IAC) valve is an electrical component and must not be soaked in any liquid cleaner or solvent. Otherwise damage could result. b. The IAC valve for this application is thread-mounted and has a dual taper, 10 mm diameter, pintle. Any replacement of the IAC valve must have the correct part number, with the appropriate pintle taper and diameter for proper seating of the valve in the throttle body. IAC Thread Mounted 10mm Pintle REMOVAL: 1. Disconnect electrical connector. 2. Remove IAC valve, use a 32 mm (1 1/4") wrench. 3. Remove IAC gasket and discard. 4. Clean old gasket material from surface of throttle body assembly to insure seal of new gasket. CLEAN: ^ Both original and replacement IAC valves have a special factory applied thread-locking compound applied to the screw threads. If the valve removed from throttle body is being reinstalled, DO NOT remove thread-locking that may remain on the threads. ^ Clean IAC valve seating surfaces on throttle body to assure proper seal of new gasket and IAC valve. Idle Air Control Valve Pintle Retraction (Manually) NOTES: a. If the IAC valve was removed during service, its operation may be tested electrically with the IAC/ISC Motor Tester (J-37027 or BT-8256K) or equivalent. Before installing a IAC valve, measure the distance between the tip of the valve pintle and the mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), the valve pintle must be retracted to prevent damage to the valve. This may be done electrically using an IAC/ISC Motor Tester or manually by exerting firm pressure, as shown in the illustration, with a slight side to side movement on valve pintle to retract it. b. No physical adjustment of the IAC valve assembly is required after installation. The IAC valve pintle is reset by turning the ignition ON for ten seconds and then OFF. The ECM then resets the pintle to the correct position. Proper idle regulation should result. INSTALLATION: 1. Install the IAC valve into throttle body with new gasket. NOTE: New IAC valves have been reset at the factory and should be installed in the throttle body in an "as is" condition, without any adjustment. 2. Tighten IAC valve assembly to 18.0 Nm (13.0 lb-ft). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Locations > Page 3661 3. Reconnect electrical connector to IAC valve. 4. "START" engine and allow it to reach operating temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 3669 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 3670 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 3671 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 3672 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Control Unit > Component Information > Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3685 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3686 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3687 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3693 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3694 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3695 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pump Relay: > 83-81-34 > Mar > 99 > SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: All Technical Service Bulletins SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3706 Fuel Pump Relay: Locations FUEL PUMP RELAY Engine Compartment Wiring, LH Side The Fuel Pump Relay is located in the RH front of cowl, above blower motor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3707 C214, Fuel Pump Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3708 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3709 Fuel Pump Relay: Service and Repair Mounted To Right Side Engine Compartment REMOVAL 1. Verify that ignition switch is in the "OFF" position. 2. Disconnect wiring harness plug. 3. Remove fuel pump relay. INSTALLATION 1. Install new fuel pump relay. 2. Reconnect wiring harness plug to relay. 3. Verify correct operation to confirm repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Idle Speed Control Motor <--> [Idle/Throttle Speed Control Unit] > Component Information > Specifications Idle Speed Control Motor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Variable Induction Control Relay > Component Information > Locations Engine Wiring - RH Cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender Oil Pressure Switch (For Fuel Pump): Locations Fuel Pump Oil Pressure Sender Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 3721 Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Fuel Pump Oil Pressure Sender > Page 3722 Oil Pressure Switch Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 3723 C121, Fuel Pump Oil Pressure Sender/Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 3724 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch Location REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 3730 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3733 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3734 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3735 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3736 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3737 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3738 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3739 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3740 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3741 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3742 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3743 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3744 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3745 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3746 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3747 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3748 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3749 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3750 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3751 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3752 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3753 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3754 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3755 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3756 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3757 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3758 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3759 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3760 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3761 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3762 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3763 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3764 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3765 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3766 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3767 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3768 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Fuel Meter Body Assembly Throttle Body: Service and Repair Fuel Meter Body Assembly Fuel Meter Body Assembly REMOVE/DISCONNECT - Electrical connections to fuel injectors. (Squeeze plastic tabs and pull straight up.) - Fuel meter cover assembly, refer to FUEL METER COVER ASSEMBLY. - Fuel injectors, refer to FUEL INJECTOR ASSEMBLIES. - Fuel inlet and outlet lines. Discard O-rings. - Fuel inlet and outlet nuts and gaskets from fuel meter body assembly. Discard gaskets. NOTE Note locations of nuts, for proper reassembly later. Inlet nut has a larger passage than outlet nut. - Fuel meter body to throttle body attaching screw assemblies. - Fuel meter body assembly from throttle body assembly. - Throttle body to fuel meter body gasket and discard. INSTALL/CONNECT - New throttle body to fuel meter gasket. Match cut-out portions in gasket with openings in throttle body. - Fuel meter body assembly on throttle body assembly. - Fuel meter body-to-throttle body attaching screw assemblies, precoated with appropriate locking compound. Tighten screw assemblies to 4.0 Nm (35.0 lb-in). - Fuel inlet and outlet nuts with new gaskets to fuel body assembly. Tighten inlet nut to 40.0 Nm (30.0 lb-ft) and outlet nut to 29.0 Nm (21.0 lb-ft). - Fuel inlet and return lines and new O-rings. (Use back-up wrench to keep TBI nuts from turning. Tighten fuel lines to 27.0 Nm (20.0 lb-ft). - Injectors with new upper and lower O-rings in fuel meter body assembly. - Fuel meter cover gasket, fuel meter outlet gasket, and pressure regulator seal. - Fuel meter cover assembly. - Long and short fuel meter cover attaching screw assemblies, coated with appropriate compound. Tighten screw assemblies to 3.0 Nm (27.0 lb-in). - Electrical connectors to fuel injectors. INSPECT Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Fuel Meter Body Assembly > Page 3773 Turn ignition switch to "ON" position for two seconds, then turn to "OFF" position for ten seconds. Again turn ignition switch to "ON" position and check for leaks around gaskets and fuel line couplings. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Fuel Meter Body Assembly > Page 3774 Throttle Body: Service and Repair Throttle Body Assembly Removal and Replacement Throttle Body Assembly - Exploded View REMOVAL: 1. Remove TBI assembly from vehicle. 2. Remove fuel meter body attaching screw assemblies. 3. Remove fuel meter body assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Fuel Meter Body Assembly > Page 3775 4. Remove throttle body to fuel meter body gasket and discard. DISASSEMBLE: Remove TPS from old throttle body, for use on new throttle body. (IAC valve does not have to be removed, since a new one comes with replacement throttle body.) ASSEMBLE: Install TPS onto replacement throttle body assembly. Refer to THROTTLE POSITION SENSOR (TPS). INSTALLATION: 1. Install new throttle body to fuel meter body gasket. 2. Install fuel meter body assembly on throttle body assembly. 3. Install fuel meter body to throttle body attaching screws that have been coated with locking compound. Tighten the attaching screw assemblies to 4.0 Nm (3.50 lb-in). 4. Install TBI unit onto intake manifold. Tighten mounting bolts to 16.0 Nm (12.0 lb-ft). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Fuel Meter Body Assembly > Page 3776 Throttle Body: Service and Repair Fuel Meter Cover Assembly WARNING: DO NOT remove the four screws securing the pressure regulator to the fuel meter cover. The fuel pressure regulator includes a large spring under heavy compression which, if accidently released, could cause personal injury. Disassembly might also be result in a fuel leak between the diaphragm and the regulator container. NOTE: The fuel meter cover assembly contains the fuel pressure regulator assembly. The regulator has been adjusted at the factory and should only be serviced as a complete assembly. Fuel Meter Cover (TBI) REMOVAL: 1. Disconnect electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up). 2. Remove long and short meter cover screw assemblies. 3. Remove fuel meter cover assembly. NOTE: DO NOT immerse fuel meter cover (with pressure regulator) in cleaner, as damage to regulator and gasket could occur. 4. Remove fuel meter outlet gasket and pressure regulator seal. Discard old gaskets and seal. INSPECTION: - Inspect for dirt, foreign material and casting warpage. INSTALLATION: 1. Install a new pressure regulator seal, fuel meter outlet passage gasket, and cover gasket. 2. Install fuel meter cover assembly. 3. Install attaching screw assemblies, precoated with appropriate locking compound to threads. (Short screws are next to injectors.) Tighten screw assemblies to 3.0 Nm (28.0 lb-in). 4. Reconnect electrical connectors to fuel injectors. 5. With engine "OFF" and ignition "ON", check for leaks around gaskets and fuel line couplings. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Fuel Meter Body Assembly > Page 3777 Throttle Body: Service and Repair Throttle Body Unit TBI Mounting REMOVAL 1. Remove air cleaner assembly and discard gasket. 2. Disconnect electrical connectors from idle air control valve (IAC), throttle position sensor (TPS), and fuel injectors (squeeze plastic tabs on injector connector and pull straight up). 3. Remove grommet with injector wires and lay aside. 4. Disconnect throttle linkage, return spring(s), transmission control cable, and cruise control (wherever applicable). 5. Disconnect vacuum hoses, noting position of hoses. 6. Disconnect inlet and outlet fuel lines. NOTE: Relieve fuel pressure before disconnecting fuel lines and use a back-up wrench on inlet and outlet nuts. 7. Remove fuel line O-rings from fuel nuts and discard. 8. Remove TBI unit mounting hardware. 9. Remove TBI unit. NOTE: To prevent damage to the throttle valve, it is essential that the unit be placed on a holding fixture, before performing service. 10. Remove TBI flange (manifold mounting) gasket. NOTE: Before removing old gasket from surface of intake manifold, stuff the manifold opening with a clean rag to prevent material from entering the engine. INSPECT ^ Manifold bore for loose parts and foreign material. ^ Intake manifold sealing surface for cleanliness. INSTALLATION 1. Install new TBI flange (manifold mounting) gasket. 2. Install TBI unit with mounting hardware. Tighten to 16.0 Nm (12.0 lb.ft.) 3. Install new O-rings on fuel line nuts and coat with new engine oil. Use a back-up wrench and tighten to 26.0 Nm (20.0 lb.ft.). 4. Connect vacuum hoses. 5. Connect throttle linkage, return spring(s), transmission control cable, and cruise control (wherever applicable). 6. Install grommet, with injector harness, to throttle body. 7. Connect electrical connectors. Ensure connectors are fully seated and latched. 8. Check to see if accelerator pedal is free, by depressing pedal to the floor and releasing, while engine is "OFF". 9. Check for fuel leaks around fuel line nuts. Apply fuel pressure by turning ignition "ON" with engine "OFF". 10. Install air cleaner assembly with new gasket. NOTE: Ensure injectors wires are not pinched between TBI and air cleaner assembly. 11. Start engine check again for fuel leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Cable/Linkage > Component Information > Service and Repair Throttle Cable/Linkage: Service and Repair Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: - The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Cable/Linkage > Component Information > Service and Repair > Page 3781 Control Cable And Linkage ACCELERATOR CONTROL CABLE When performing service on the accelerator control cable, observe the following: - The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud or release cable from pulley. - Retainer locking tangs from support bracket. - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel. INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications ENGINE COOLANT TEMPERATURE (ECT) SENSOR 212°F or (100°C) ................................................................................................................................. ................................................................ 177 Ohms 158°F or (70°C) ................................................................................................................................... ................................................................ 467 Ohms 100°F or (38°C) ................................................................................................................................... .............................................................. 1800 Ohms 68°F or (20°C) ..................................................................................................................................... ............................................................. 3520 Ohms 40°F or (4°C) ....................................................................................................................................... .............................................................. 7500 Ohms 20°F or (-7°C) ...................................................................................................................................... ........................................................... 13,500 Ohms 0°F or (-18°C) ...................................................................................................................................... ........................................................... 25,000 Ohms -40°F or (-40°C) ................................................................................................................................... ......................................................... 100,700 Ohms IDLE AIR CONTROL (IAC) VALVE Terminals "A" to "B" ............................................................................................................................. ....................................................... 40 to 80 Ohms Terminals "C" to "D" ............................................................................................................................ ........................................................ 40 to 80 Ohms Terminals "B" to "C" ............................................................................................................................. ........................................................ Infinite Ohms Terminals "A" to "D" ............................................................................................................................. ........................................................ Infinite Ohms MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1,000 to 2,000 Feet ............................................................................................................................. ......................................................... 3.6 to 5.2 Volts 2,000 to 3,000 Feet ............................................................................................................................. ......................................................... 3.5 to 5.1 Volts 3,000 to 4,000 Feet ............................................................................................................................. ......................................................... 3.3 to 5.0 Volts 4,000 to 5,000 Feet ............................................................................................................................. ......................................................... 3.2 to 4.8 Volts 5,000 to 6,000 Feet ............................................................................................................................. ......................................................... 3.0 to 4.6 Volts 6,000 to 7,000 Feet ............................................................................................................................. ......................................................... 2.9 to 4.5 Volts 7,000 to 8,000 Feet ............................................................................................................................. ......................................................... 2.8 to 4.3 Volts 8,000 to 9,000 Feet ............................................................................................................................. ......................................................... 2.6 to 4.2 Volts 9,000 to 10,000 Feet ........................................................................................................................... .......................................................... 2.5 to 4.0 Volts OXYGEN (O2S) SENSOR Closed Loop ............................................................................................................................................................. 100 mV (.1 volt) to .999 mV (1.0 volt) THROTTLE POSITION SENSOR Idle (normal) ........................................................................................................................................ ......................................................... .45 to .95 volts. (maximum) ........................................................................................................................................... ........................................................ 1.25 volts. Wide Open Throttle ............................................................................................................................. ......................................................... 4.0 to 4.5 volts. The Throttle position Sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View Throttle Position (TP) Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Locations > Assembly View > Page 3787 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3790 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3791 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3792 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3793 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3794 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3795 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3796 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3797 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3798 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3799 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3800 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3801 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3802 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3803 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3804 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3805 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3806 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3807 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3808 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3809 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3810 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3811 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3812 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3813 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3814 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3815 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3816 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3817 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3818 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3819 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3820 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3821 C105, TP Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3822 Throttle Position Sensor Circuit Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3823 Throttle Position Sensor: Description and Operation Throttle Position Sensor (TPS) Circuit NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Throttle Position Sensor (TPS) is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground, and the other to the computer 5 volt reference source. A third wire from the computer is used to measure the output voltage from the TPS. As the throttle angle changes (pressing down on accelerator pedal) so does the TPS voltage output. By monitoring TPS voltage output, the computer can determine fuel delivery rate based on throttle valve angle or driver demand. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3824 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3825 Throttle Position Sensor: Service and Repair NOTE: Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. With throttle valve in normally closed position, install TPS on throttle shaft and rotate counter clockwise to align mounting hole. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Variable Induction System > Variable Induction Control Relay > Component Information > Locations Engine Wiring - RH Cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark 4.3L (M/L) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Locations Distributor And Coil 4.3L Engine Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation Distributor: Service and Repair Removal & Installation Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 3848 Distributor And Coil 4.3L Engine Distributor And Coil 5.0L And 5.7L (TBI) Engines Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 3849 Distributor And Coil - 7.4L Engine Removal: NOTE:Verify ignition switch is "OFF". 1. Disconnect wiring harness connectors at side of distributor. 2. Remove coil wire and sparkplug wires on either the left or right side of the distributor. 3. Remove distributor cap by the two screws and set to side: A. Bring engine to TDC on the compression stroke for the #1 cylinder and align timing marks to 0~ . B. Scribe a mark on the distributor housing in line with the rotor. C. Scribe a mark on the engine in line with the rotor. D. Note position of the distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. Installation: NOTE:To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Install distributor and gasket (if applicable). 2. Install hold-down clamp and tighten bolt: ^ Bolt on the 2.8R to 35 Nm (26 lb. ft.). ^ Bolt on the 4.3Z, 5.0H, 5.7K & 7.4N to 35 Nm (25 lb. ft.) 3. Install distributor cap. 4. Connect wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 3850 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components Removal: 1. With distributor removed, disconnect wires at module terminals 2. Remove roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Remove gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Remove distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. Installation: 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Service and Repair > Removal & Installation > Page 3851 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Spark Plug Wire <--> [Ignition Cable] > Component Information > Specifications > Page 3855 Spark Plug Wire Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications Ignition Coil: Specifications COIL PACK RESISTANCE SPECIFICATIONS: ^ The OEM service manual does not give a specification for coil resistance and recommends to test all other ignition components first and then switch affected coil with a good known coil and retest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 3859 Ignition Coil: Locations Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 3860 Distributor And Coil 4.3L Engine Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 3861 C152, Ignition Coil Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 3862 Ignition Coil: Service and Repair REMOVAL: NOTE: Make sure ignition switch is "OFF". 1. Disconnect wiring connectors at side of the coil. 2. Disconnect coil to distributor lead at coil. 3. Remove nuts or screws holding coil bracket and coil to engine. 4. Remove coil bracket and coil. ^ Drill and punch out rivets holding coil to coil bracket. 5. Remove coil from coil bracket. INSTALLATION: 1. Install coil to coil bracket with screws. 2. Install coil and coil bracket to engine. Tighten screws to 22 N-m (16 lb. ft.). 3. Connect distributor lead to coil . 4. Connect wiring connectors to the coil. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Control Module > Component Information > Diagrams C103, Ignition Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Control Module > Component Information > Diagrams > Page 3866 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: NOTE: It is not necessary to remove ignition distributor assembly from engine. 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. Tighten to 2 Nm (18 lb. in.) 4. Install pick up coil. 5. Install cap and rotor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 3871 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 3874 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 3875 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 3876 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 3877 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 3878 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Diagrams C103, Ignition Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Diagrams > Page 3883 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: NOTE: It is not necessary to remove ignition distributor assembly from engine. 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. Tighten to 2 Nm (18 lb. in.) 4. Install pick up coil. 5. Install cap and rotor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 3889 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensor: Locations Assembly View Knock Sensor (KS) Location The Knock Sensors (KS) are mounted in the right rear cylinder head and the left cylinder head between the rear spark plugs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 3892 Knock Sensor: Locations Knock Sensor, Rear Engine Wiring, RH Side And Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 3893 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3894 C114, Knock Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3895 Knock Sensor: Description and Operation Knock Sensor (KS) Circuit Diagram NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The knock sensor is located in the engine block and sends a signal to the control module to retard ignition timing during a spark knock condition. When the knock sensor senses no more knocking the control module advances timing in small increments. This allows the control module to maintain maximum timing advance under various conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3896 Knock Sensor: Service and Repair REMOVAL 1. Disconnect battery cable. 2. Drain cooling system. 3. Disconnect wiring harness connector from knock sensor. 4. Remove knock sensor. INSTALLATION 1. Install knock sensor. Apply water base caulk to sensor threads. Do not use silicon tape as this will insulate sensor from engine. Tighten to 19 Nm (14 lb. ft.). 2. Connect wiring harness connector to knock sensor. 3. Connect negative battery cable. 4. Refill cooling system and pressure test for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ............................................................... .045 inches Spark Plug Torque ............................................................................................................................... ..................................................... 15 Nm (11 lb. ft.) Spark Plug Type .................................................................................................................................. .............................................................. AC CR43TS NOTE: Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations Shift Interlock Solenoid: Locations Steering Column Wiring Steering Column Wiring Inside Steering Column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations > Page 3906 C218A, BTSI Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 3911 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 3914 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN ^ Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). ^ Filter seal may be stuck in the pump. INSPECT ^ Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3917 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3918 Manual Valve Link Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3919 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with 0-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3920 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). ^ Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3921 Case Checkballs And Filters TOOL REQUIRED: ^ J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. ^ The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. ^ Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). ^ Gasket (47) identified by a "C". Gasket (52) identified by a "V". ^ Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT ^ Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3922 Case Checkballs And Filters Filter Screen - Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3923 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3924 Control Valve Assembly - Legend Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3925 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3926 Manual Valve Link Outside Electrical Connector CLEAN ^ Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT ^ Some valves are under pressure - cover the bores while removing roll pins and retainer clips. ^ Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3927 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN ^ All valves, springs, bushings and control valve body in clean solvent. ^ Dry using compressed air. INSPECT ^ All valves and bushings for: Porosity - Scoring - Nicks - Scratches ^ Springs for damaged or distorted coils. ^ Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE ^ Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). ^ Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). ^ Connect the manual valve link (89) to the inside detent lever (88). ^ Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT ^ Wiring harness connections to electrical components. ^ To correctly hook up the wires, see the wiring diagrams. ^ The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN ^ Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). ^ The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3928 TIGHTEN ^ Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN ^ Torque to 12 Nm (9 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3929 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT ^ Seal (29) is reusable. 4. Filter assembly (31). INSPECT ^ Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3930 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3931 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. ^ Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five 0-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3932 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT ^ Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3933 ^ Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN ^ All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. ^ Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. 2. Pistons for: ^ Seal damage. 3. Springs for: ^ Damaged or distorted coils. 4. Valve body casting and accumulator housing for: ^ Porosity. ^ Cracks. ^ Interconnected passages. ^ Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3934 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3935 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3936 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3937 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3938 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN ^ Control valve assembly and accumulator housing (51) thoroughly in clean solvent. ^ Air dry. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3939 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3940 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3941 CLEAN ^ All components. INSPECT ^ All valves, pistons, springs and seals for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3942 ASSEMBLE ^ Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE ^ Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3943 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: ^ Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3944 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN ^ Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3945 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3946 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. ^ # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3947 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT ^ Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN ^ Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3948 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. ^ Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 3949 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN ^ Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Description and Operation Torque Converter Clutch Solenoid: Description and Operation OPERATION: The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two conditions must be met. 1. Internal transmission fluid pressure must be correct. 2. The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. This allows the converter clutch to apply, if the hydraulic pressure is correct. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations Shift Interlock Relay: Locations Behind LH side of I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations > Page 3958 Shift Interlock Relay: Diagrams C217A, Brake/Transmission Shift Interlock Relay C218A, Brake/Transmission Shift Interlock Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 3964 Brake Switch - TCC: Diagrams C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 3968 Fluid Pressure Sensor/Switch: Locations The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 3969 Fluid Pressure Sensor/Switch: Description and Operation Pressure Switch Manifold NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Pressure Switch Manifold (PSM) is a gear range sensing device used by the control module to sense what gear has been selected by the vehicle operator. The PSM is located on the valve body and consists of five pressure switches combined into one unit. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 3974 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 3975 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 3976 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 3977 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly Technical Service Bulletin # 99046 Date: 991201 Recall - High/Low/High ABS Brake Anomaly File in Section: Special Prices Bulletin No.: 99046 Date: December, 1999 SPECIAL POLICY SUBJECT: 99046 - SPECIAL POLICY - HIGH/LOW/HIGH ABS BRAKE ANOMALY MODELS: 1993-1996 CHEVROLET, GMC, AND OLDSMOBILE S/T UTILITY 1994-1996 CHEVROLET AND GMC S/T PICKUP EQUIPPED WITH A V6 ENGINE 1993-1995 CHEVROLET AND GMC M/L VAN 1993-1996 CHEVROLET AND GMC G VAN THIS SPECIAL POLICY IS IN EFFECT UNTIL DECEMBER 1, 2002 DUE TO THE AVAILABILITY OF PARTS, THIS SPECIAL POLICY WILL BE ADMINISTERED IN PHASES. THIS FIRST PHASE WILL BE THE REPROGRAMMING OF THE VCM IN 2WD AND 4WD 1994-1996 S/T PICKUPS AND 1995-1996 S/T UTILITIES EQUIPPED WITH A VCM. VEHICLES INVOLVED IN PHASE 1 ARE SHADED IN THE TABLE. YOU WILL BE NOTIFIED OF THE NEXT PHASE VIA DCS MESSAGE. Condition The federal government's highway safety agency, the National Highway Traffic Safety Administration (NHTSA) has identified, and General Motors Corporation has confirmed, the existence of a condition in the antilock braking system of some Chevrolet, GMC, and Oldsmobile S/T utilities. 1994-1996 Chevrolet and GMC S/T pickups equipped with a V6 engine, 1993-1995 Chevrolet and GMC M/L vans, and 1993-1996 Chevrolet and GMC G vans, all equipped with the Lucas Varity three-sensor ABS system. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If the customer is driving on a road surface that supports good traction and they begin to stop by applying the brake pedal firmly, and both front wheels of their vehicle then pass onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), the antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow the customer to steer and maintain stability, which is normal ABS operation1 as their owner's manual explains in more detail. However, if the customer is still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. The ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. SPECIAL POLICY ADJUSTMENT (Phase I) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 3989 This special policy adjustment covers the condition described above- until December 1, 2002, regardless of vehicle mileage or ownership. Dealers are to reprogram the VCM. Use the following Service Procedure. This will be performed at no charge to the customer during this time. Other conditions that may cause similar or different brake complaints that are not a result of the condition listed above are not covered by this special policy. The customer should be informed that any further service that is not covered by this special policy would be their responsibility, if they elect to have the service performed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 3990 VEHICLES INVOLVED Involved are 1993-1998 S/T utilities, 1994-1996 S/T pickups equipped with a V6 engine, 1993-1995 M/L van, and 1993-1996 G vans built within the VIN breakpoints. PARTS INFORMATION This phase requires no parts. Calibrations are available in October, 1999 on TIS 2000 CD, # 21 or Techline CD # 20/21 or later versions. CUSTOMER NOTIFICATION Customers will be notified of this special policy on their vehicles, in phases, by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly). SERVICE PROCEDURE VCM Programming Important: For 1995 S/T utilities with L35, check the Service Parts Identification (SPID) label on the inside of the glovebox to determine if the vehicle has a VCM. If there is an RPO of "K29", the vehicle has a PCM and is programmable. The new calibration,will be available in October, 1999 on TIS 2000 CD # 21 or Techline CD # 20/21 and later versions. The calibration is programmed into the vehicle's VCM via a Techline TOOL. Use a Techline Terminal or scan tool to perform the learn procedure and program the VCM. Important: Use the calibration file "Special Policy 99046" on TIS 2000 CD # 21 or Techline CD # 20/21 or later versions. 1. To ensure VCM programming/RPO configuration, confirm that the following conditions exist in order to prepare for VCM programming: ^ The battery is fully charged ^ The ignition switch is in the "RUN" position ^ The Data Link Connector (DLC) is accessible 2. Refer to the latest Techline Terminal and equipment user's instructions. 3. Clear the diagnostic trouble codes (DTCs) after the programming is complete. CLAIM INFORMATION For vehicles repaired under warranty submit a claim with the information indicated. Owner Letter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 3991 December, 1999 Dear Chevrolet/GMC Customer: As the owner of a General Motors truck equipped with the Lucas Varity three-sensor antilock brake system (ABS), your satisfaction with our product is of utmost concern to us. Condition: The federal government's highway safety agency. the National Highway Traffic Safety Administration (NHTSA) has identifled1 and General Motors Corporation has confirmed the existence of a condition in the antilock braking system of some Chevrolet and GMC 1994-1996 S/T pickups equipped with a V6 engine and 1995-1996 S/T utility vehicles. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If you're driving on a road surface that supports good traction and you begin to stop by applying your brake pedal firmly, and both front wheels of your vehicle then pass, onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), your antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow you to steer and maintain stability, which is normal ABS operation, as your owner's manual explains in more detail. However, if you are still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. Your ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. Therefore, GM has developed a software change that will make your vehicle less Sensitive to wheel slip under the circumstances described above. What Will Be Done: Upon your request, your Chevrolet/GMC dealer will make a change to your antilock braking system software to prevent this phenomenon from occurring. This software change will have only a slight effect on vehicle steerablity during braking on very slippery surfaces and is designed to have no effect on normal ABS or other braking operations. This change should not affect how your brakes feel or create any perceptible difference in the steerability or stability of your vehicle while braking. This modification will be performed for you at no charge at anytime until December 1, 2002. How Long Will The Repair Take: Your Chevrolet/GMC dealer will modify your vehicle's ABS software. We estimate that it will take your dealer 45 minutes to perform this modification. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed. Contacting Your Dealer: Repairs and adjustments qualifying under this special coverage must be performed by a Chevrolet/GMC dealer. You may want to call the service department to arrange a convenient appointment. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below: Deaf, Hearing Impaired Division Number or Speech Impaired* Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 * Utilizes Telecommunication Devices for the Deaf/Text Telephones (TDD/TTY) 1-800-462-8782. The deaf, hearing impaired, or speech impaired should call 1-800-462-8583 (utilizes Telecommunication Devices for the Deaf/Text Telephones, TDD/TTY). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM PROM - Programmable Read Only Memory: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 3997 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 3998 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 3999 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4000 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4001 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4002 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4003 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly Technical Service Bulletin # 99046 Date: 991201 Recall - High/Low/High ABS Brake Anomaly File in Section: Special Prices Bulletin No.: 99046 Date: December, 1999 SPECIAL POLICY SUBJECT: 99046 - SPECIAL POLICY - HIGH/LOW/HIGH ABS BRAKE ANOMALY MODELS: 1993-1996 CHEVROLET, GMC, AND OLDSMOBILE S/T UTILITY 1994-1996 CHEVROLET AND GMC S/T PICKUP EQUIPPED WITH A V6 ENGINE 1993-1995 CHEVROLET AND GMC M/L VAN 1993-1996 CHEVROLET AND GMC G VAN THIS SPECIAL POLICY IS IN EFFECT UNTIL DECEMBER 1, 2002 DUE TO THE AVAILABILITY OF PARTS, THIS SPECIAL POLICY WILL BE ADMINISTERED IN PHASES. THIS FIRST PHASE WILL BE THE REPROGRAMMING OF THE VCM IN 2WD AND 4WD 1994-1996 S/T PICKUPS AND 1995-1996 S/T UTILITIES EQUIPPED WITH A VCM. VEHICLES INVOLVED IN PHASE 1 ARE SHADED IN THE TABLE. YOU WILL BE NOTIFIED OF THE NEXT PHASE VIA DCS MESSAGE. Condition The federal government's highway safety agency, the National Highway Traffic Safety Administration (NHTSA) has identified, and General Motors Corporation has confirmed, the existence of a condition in the antilock braking system of some Chevrolet, GMC, and Oldsmobile S/T utilities. 1994-1996 Chevrolet and GMC S/T pickups equipped with a V6 engine, 1993-1995 Chevrolet and GMC M/L vans, and 1993-1996 Chevrolet and GMC G vans, all equipped with the Lucas Varity three-sensor ABS system. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If the customer is driving on a road surface that supports good traction and they begin to stop by applying the brake pedal firmly, and both front wheels of their vehicle then pass onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), the antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow the customer to steer and maintain stability, which is normal ABS operation1 as their owner's manual explains in more detail. However, if the customer is still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. The ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. SPECIAL POLICY ADJUSTMENT (Phase I) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4009 This special policy adjustment covers the condition described above- until December 1, 2002, regardless of vehicle mileage or ownership. Dealers are to reprogram the VCM. Use the following Service Procedure. This will be performed at no charge to the customer during this time. Other conditions that may cause similar or different brake complaints that are not a result of the condition listed above are not covered by this special policy. The customer should be informed that any further service that is not covered by this special policy would be their responsibility, if they elect to have the service performed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4010 VEHICLES INVOLVED Involved are 1993-1998 S/T utilities, 1994-1996 S/T pickups equipped with a V6 engine, 1993-1995 M/L van, and 1993-1996 G vans built within the VIN breakpoints. PARTS INFORMATION This phase requires no parts. Calibrations are available in October, 1999 on TIS 2000 CD, # 21 or Techline CD # 20/21 or later versions. CUSTOMER NOTIFICATION Customers will be notified of this special policy on their vehicles, in phases, by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly). SERVICE PROCEDURE VCM Programming Important: For 1995 S/T utilities with L35, check the Service Parts Identification (SPID) label on the inside of the glovebox to determine if the vehicle has a VCM. If there is an RPO of "K29", the vehicle has a PCM and is programmable. The new calibration,will be available in October, 1999 on TIS 2000 CD # 21 or Techline CD # 20/21 and later versions. The calibration is programmed into the vehicle's VCM via a Techline TOOL. Use a Techline Terminal or scan tool to perform the learn procedure and program the VCM. Important: Use the calibration file "Special Policy 99046" on TIS 2000 CD # 21 or Techline CD # 20/21 or later versions. 1. To ensure VCM programming/RPO configuration, confirm that the following conditions exist in order to prepare for VCM programming: ^ The battery is fully charged ^ The ignition switch is in the "RUN" position ^ The Data Link Connector (DLC) is accessible 2. Refer to the latest Techline Terminal and equipment user's instructions. 3. Clear the diagnostic trouble codes (DTCs) after the programming is complete. CLAIM INFORMATION For vehicles repaired under warranty submit a claim with the information indicated. Owner Letter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4011 December, 1999 Dear Chevrolet/GMC Customer: As the owner of a General Motors truck equipped with the Lucas Varity three-sensor antilock brake system (ABS), your satisfaction with our product is of utmost concern to us. Condition: The federal government's highway safety agency. the National Highway Traffic Safety Administration (NHTSA) has identifled1 and General Motors Corporation has confirmed the existence of a condition in the antilock braking system of some Chevrolet and GMC 1994-1996 S/T pickups equipped with a V6 engine and 1995-1996 S/T utility vehicles. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If you're driving on a road surface that supports good traction and you begin to stop by applying your brake pedal firmly, and both front wheels of your vehicle then pass, onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), your antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow you to steer and maintain stability, which is normal ABS operation, as your owner's manual explains in more detail. However, if you are still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. Your ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. Therefore, GM has developed a software change that will make your vehicle less Sensitive to wheel slip under the circumstances described above. What Will Be Done: Upon your request, your Chevrolet/GMC dealer will make a change to your antilock braking system software to prevent this phenomenon from occurring. This software change will have only a slight effect on vehicle steerablity during braking on very slippery surfaces and is designed to have no effect on normal ABS or other braking operations. This change should not affect how your brakes feel or create any perceptible difference in the steerability or stability of your vehicle while braking. This modification will be performed for you at no charge at anytime until December 1, 2002. How Long Will The Repair Take: Your Chevrolet/GMC dealer will modify your vehicle's ABS software. We estimate that it will take your dealer 45 minutes to perform this modification. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed. Contacting Your Dealer: Repairs and adjustments qualifying under this special coverage must be performed by a Chevrolet/GMC dealer. You may want to call the service department to arrange a convenient appointment. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below: Deaf, Hearing Impaired Division Number or Speech Impaired* Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 * Utilizes Telecommunication Devices for the Deaf/Text Telephones (TDD/TTY) 1-800-462-8782. The deaf, hearing impaired, or speech impaired should call 1-800-462-8583 (utilizes Telecommunication Devices for the Deaf/Text Telephones, TDD/TTY). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99-06-04-053 > Nov > 99 > PROM - Powertrain Control Module Reprogramming PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4020 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4021 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4022 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4023 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4024 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4025 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4026 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming PROM - Programmable Read Only Memory: All Technical Service Bulletins SPS/FLASH EPROM Programming File In Section: 6E - Engine Fuel & Emission Bulletin No.: 53-65-08 Date: January, 1996 INFORMATION Subject: SPS/FLASH EPROM Programming Models: 1993-96 Passenger Cars and Trucks Applicable Reprogrammable Vehicles This bulletin is being issued to assist technicians in reprogramming vehicles and should be used in conjunction with instructions provided on your Techline Terminal and in your Techline Terminal User's Manual. THE TECHLINE TERMINAL (T-20, T-50, T-60) HAS BEEN ABLE TO DO 1996 VEHICLE PROGRAMMING THROUGH THE DIRECT METHOD SINCE 1996 VEHICLES HAVE BEEN AVAILABLE IN THE DEALERSHIPS/RETAIL FACILITIES. THE TECHLINE CD-ROM TITLED DISC 13 CONTAINS THE SOFTWARE NEEDED TO PROGRAM ALL 1996 VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD). SPS Tips 1. BATTERY VOLTAGE SHOULD BE CHECKED. A FULLY CHARGED BATTERY IS NECESSARY BEFORE REPROGRAMMING TAKES PLACE. THE VEHICLE BATTERY SHOULD NOT BE CONNECTED TO A BATTERY CHARGER DURING A PROGRAMMING EVENT INCORRECT VOLTAGE COULD CAUSE PROGRAMMING AND/OR CONTROL MODULE FAILURE. During programming, the control module depends on the battery as its sole source of power. Also during programming, the vehicle's components (i.e. blower motor) are set to a default mode which may be turned on, placing additional draw on the vehicle's battery. If the voltage goes outside the specified range (11 to 14 volts) the controllers and the Techline equipment will stop communicating. If this happens, it could cause the control module to become inoperable and require replacement. 2. CHECK THE INTEGRITY OF THE TECH 1 CABLES, MAKE SURE THEY ARE NOT FRAYED, BROKEN OR TWISTED. Loss of communication for any reason will require additional time in completing the reprogramming event. 3. IF USING A TECH 1, YOUR MASS STORAGE CARTRIDGE (MSC) MUST BE UPDATED TO REFLECT THE MOST CURRENT UPDATE OFFERED ON THE TECHLINE CD-ROM. DISC 13, 1995 WAS THE FIRST CD-ROM THAT HAD REMOTE PROGRAMMING SUPPORT If your MSC is not updated to reflect the current software version on the Techline Terminal, in some situations the software will not be capable of interpreting the information that is requested from the vehicle. 4. T-100 TERMINALS (CAMS) ARE NOT CAPABLE OF PROGRAMMING OBD II VEHICLES THROUGH THE DIRECT METHOD. A TECH 1 MUST BE USED (REMOTE METHOD) WHEN REPROGRAMMING WITH A T-100. The T-100 terminals communicate with vehicles through a DLC (ALDL) card and cable found within the T-100's computer. The DLC (ALDL) card is not capable of communicating at the new baud rate used with OBD II. 5. PROGRAMMING IS NOT NEEDED IF THE CURRENT CALIBRATION IS THE SAME AS THE SELECTED CALIBRATION. 6. IF PROGRAMMING A NEW CONTROL MODULE, YOU MUST REQUEST INFORMATION FROM THE NEW CONTROL MODULE. The security information that is needed for a control module to be programmed is stored in the new control module. The security information must be requested from the control module to be programmed. At that point, the control module can be successfully programmed. This requesting of security information takes place in both the direct and remote methods. The request is automatic when using the direct method. Looking at the calibration stored in the old controller may be helpful in selecting the calibration from the CD-ROM for the new controller. 7. WHEN PROGRAMMING OBD II VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD), A VEHICLE INTERFACE MODULE (VIM) IS REQUIRED. The VIM allows the Tech 1 to communicate with the OBD II vehicles. The VIM is necessary for all other Tech 1 diagnostics on OBD II vehicles. VIMs are no longer on backorder. If you are interested in obtaining additional VIMs, call 1-800-GM-TOOLS and ask for VIM kit part number 7000041. 8. DISCONNECT THE TECH I AND VIM FROM THE VEHICLE BETWEEN RETRIEVING DATA AND PROGRAMMING THE VEHICLE. If the VIM remains powered up after data is requested, a communication problem may result when the reprogramming function is performed. 9. WHEN CONNECTING THE TECH 1 TO A TECHLINE TERMINAL (EXCEPT T-100 CAMS), ALWAYS CONNECT THE FLAT GRAY R5232 CABLE FIRST AND THEN THE POWER ADAPTER. FAILURE TO DO SO COULD RESULT IN A LOSS OF INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4031 STORED ON THE TECH 1. When power is turned on to the Tech 1, it looks for the RS232 connection. If it does not see the connection, the Tech 1 in some cases, will erase the information stored for download. 10. DO NOT DISCONTINUE OR INTERRUPT THE PROGRAM LOADING PROCESS TO THE VEHICLE. This will result in a programming error and could prevent the Electronic Control Module (ECM) from functioning properly. 11. AFTER PROGRAMMING IS COMPLETE, PRESS "EXIT". MAKE SURE THE KEY IS CYCLED OFF FOR APPROXIMATELY 10 SECONDS THEN BACK ON. Some vehicles will lose component settings (PMC/IAC Valve). Cycling the key off two times (Off for 30 seconds, On for 10 then repeat a second time) will allow for resetting of the components. Start the vehicle to ensure programming was successful. FOR CADILLAC VEHICLES ONLY a. DUE TO OTHER MODULES ON THE DATA LINE TRYING TO COMMUNICATE WITH THE ECM DURING PROGRAMMING, SOME COMMUNICATION CODES MAY BE SET After programming is complete, clear any codes and verify they do not reset. b. TO HELP MINIMIZE BATTERY DRAW DURING ECM PROGRAMMING, DISCONNECT THE BLOWER MOTOR (AT THE CONNECTOR, NOT THE FUSE) PRIOR TO PROGRAMMING. When programming is complete, reconnect the blower motor. 12. 1997 VEHICLES REQUIRE REPROGRAMMING BE DONE USING A TECH 2. OBD II vehicle calibration size and complexity will require more memory than the Tech 1 has available. Tech 2 will be an essential tool in the first quarter of 1996 containing limited 1996 applications and updates. 13. STG HAS ISSUED BULLETINS (# 53-65-04 and # 53-65-05 - (SEE CHART EXCERPTED FROM 53-65-05 FOR USE AS A QUICK REFERENCE GUIDE), DEVELOPED QUICK REFERENCE GUIDES (P/N SPSCARD-1 AVAILABLE THROUGH YOUR LOCAL GM TRAINING CENTER), PRODUCED CPT VIDEOS (CPT # 56010.00-B), HAD PULSAT BROADCASTS, AND OFFERS GM TRAINING CENTER CLASSROOM COURSES. As you work through reprogramming, keep the above-mentioned material in mind as resources to assist you if difficulty is encountered. As always, the Techline Customer Support Center (1-800-828-6860 English, 1-800-503-3222 French) is always available to assist the technician with any situation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4032 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4033 SPS/EEPROM Programming 1993 to current Reprogrammable Vehicles Note: If programming a new control module you must request info from the new control module first. Battery voltage should be checked and at full charge before reprogramming takes place. System to be programmed should NOT be connected to a battery charger. Incorrect voltage could cause programming and/or control module failure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4038 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4039 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4040 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4041 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4042 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4043 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4044 Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4054 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4055 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4056 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4057 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4058 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4059 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4060 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly Technical Service Bulletin # 99046 Date: 991201 Recall - High/Low/High ABS Brake Anomaly File in Section: Special Prices Bulletin No.: 99046 Date: December, 1999 SPECIAL POLICY SUBJECT: 99046 - SPECIAL POLICY - HIGH/LOW/HIGH ABS BRAKE ANOMALY MODELS: 1993-1996 CHEVROLET, GMC, AND OLDSMOBILE S/T UTILITY 1994-1996 CHEVROLET AND GMC S/T PICKUP EQUIPPED WITH A V6 ENGINE 1993-1995 CHEVROLET AND GMC M/L VAN 1993-1996 CHEVROLET AND GMC G VAN THIS SPECIAL POLICY IS IN EFFECT UNTIL DECEMBER 1, 2002 DUE TO THE AVAILABILITY OF PARTS, THIS SPECIAL POLICY WILL BE ADMINISTERED IN PHASES. THIS FIRST PHASE WILL BE THE REPROGRAMMING OF THE VCM IN 2WD AND 4WD 1994-1996 S/T PICKUPS AND 1995-1996 S/T UTILITIES EQUIPPED WITH A VCM. VEHICLES INVOLVED IN PHASE 1 ARE SHADED IN THE TABLE. YOU WILL BE NOTIFIED OF THE NEXT PHASE VIA DCS MESSAGE. Condition The federal government's highway safety agency, the National Highway Traffic Safety Administration (NHTSA) has identified, and General Motors Corporation has confirmed, the existence of a condition in the antilock braking system of some Chevrolet, GMC, and Oldsmobile S/T utilities. 1994-1996 Chevrolet and GMC S/T pickups equipped with a V6 engine, 1993-1995 Chevrolet and GMC M/L vans, and 1993-1996 Chevrolet and GMC G vans, all equipped with the Lucas Varity three-sensor ABS system. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If the customer is driving on a road surface that supports good traction and they begin to stop by applying the brake pedal firmly, and both front wheels of their vehicle then pass onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), the antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow the customer to steer and maintain stability, which is normal ABS operation1 as their owner's manual explains in more detail. However, if the customer is still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. The ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. SPECIAL POLICY ADJUSTMENT (Phase I) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4066 This special policy adjustment covers the condition described above- until December 1, 2002, regardless of vehicle mileage or ownership. Dealers are to reprogram the VCM. Use the following Service Procedure. This will be performed at no charge to the customer during this time. Other conditions that may cause similar or different brake complaints that are not a result of the condition listed above are not covered by this special policy. The customer should be informed that any further service that is not covered by this special policy would be their responsibility, if they elect to have the service performed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4067 VEHICLES INVOLVED Involved are 1993-1998 S/T utilities, 1994-1996 S/T pickups equipped with a V6 engine, 1993-1995 M/L van, and 1993-1996 G vans built within the VIN breakpoints. PARTS INFORMATION This phase requires no parts. Calibrations are available in October, 1999 on TIS 2000 CD, # 21 or Techline CD # 20/21 or later versions. CUSTOMER NOTIFICATION Customers will be notified of this special policy on their vehicles, in phases, by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly). SERVICE PROCEDURE VCM Programming Important: For 1995 S/T utilities with L35, check the Service Parts Identification (SPID) label on the inside of the glovebox to determine if the vehicle has a VCM. If there is an RPO of "K29", the vehicle has a PCM and is programmable. The new calibration,will be available in October, 1999 on TIS 2000 CD # 21 or Techline CD # 20/21 and later versions. The calibration is programmed into the vehicle's VCM via a Techline TOOL. Use a Techline Terminal or scan tool to perform the learn procedure and program the VCM. Important: Use the calibration file "Special Policy 99046" on TIS 2000 CD # 21 or Techline CD # 20/21 or later versions. 1. To ensure VCM programming/RPO configuration, confirm that the following conditions exist in order to prepare for VCM programming: ^ The battery is fully charged ^ The ignition switch is in the "RUN" position ^ The Data Link Connector (DLC) is accessible 2. Refer to the latest Techline Terminal and equipment user's instructions. 3. Clear the diagnostic trouble codes (DTCs) after the programming is complete. CLAIM INFORMATION For vehicles repaired under warranty submit a claim with the information indicated. Owner Letter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4068 December, 1999 Dear Chevrolet/GMC Customer: As the owner of a General Motors truck equipped with the Lucas Varity three-sensor antilock brake system (ABS), your satisfaction with our product is of utmost concern to us. Condition: The federal government's highway safety agency. the National Highway Traffic Safety Administration (NHTSA) has identifled1 and General Motors Corporation has confirmed the existence of a condition in the antilock braking system of some Chevrolet and GMC 1994-1996 S/T pickups equipped with a V6 engine and 1995-1996 S/T utility vehicles. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If you're driving on a road surface that supports good traction and you begin to stop by applying your brake pedal firmly, and both front wheels of your vehicle then pass, onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), your antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow you to steer and maintain stability, which is normal ABS operation, as your owner's manual explains in more detail. However, if you are still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. Your ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. Therefore, GM has developed a software change that will make your vehicle less Sensitive to wheel slip under the circumstances described above. What Will Be Done: Upon your request, your Chevrolet/GMC dealer will make a change to your antilock braking system software to prevent this phenomenon from occurring. This software change will have only a slight effect on vehicle steerablity during braking on very slippery surfaces and is designed to have no effect on normal ABS or other braking operations. This change should not affect how your brakes feel or create any perceptible difference in the steerability or stability of your vehicle while braking. This modification will be performed for you at no charge at anytime until December 1, 2002. How Long Will The Repair Take: Your Chevrolet/GMC dealer will modify your vehicle's ABS software. We estimate that it will take your dealer 45 minutes to perform this modification. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed. Contacting Your Dealer: Repairs and adjustments qualifying under this special coverage must be performed by a Chevrolet/GMC dealer. You may want to call the service department to arrange a convenient appointment. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below: Deaf, Hearing Impaired Division Number or Speech Impaired* Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 * Utilizes Telecommunication Devices for the Deaf/Text Telephones (TDD/TTY) 1-800-462-8782. The deaf, hearing impaired, or speech impaired should call 1-800-462-8583 (utilizes Telecommunication Devices for the Deaf/Text Telephones, TDD/TTY). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99-06-04-053 > Nov > 99 > PROM - Powertrain Control Module Reprogramming PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4077 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4078 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4079 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4080 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4081 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4082 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4083 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming PROM - Programmable Read Only Memory: All Technical Service Bulletins SPS/FLASH EPROM Programming File In Section: 6E - Engine Fuel & Emission Bulletin No.: 53-65-08 Date: January, 1996 INFORMATION Subject: SPS/FLASH EPROM Programming Models: 1993-96 Passenger Cars and Trucks Applicable Reprogrammable Vehicles This bulletin is being issued to assist technicians in reprogramming vehicles and should be used in conjunction with instructions provided on your Techline Terminal and in your Techline Terminal User's Manual. THE TECHLINE TERMINAL (T-20, T-50, T-60) HAS BEEN ABLE TO DO 1996 VEHICLE PROGRAMMING THROUGH THE DIRECT METHOD SINCE 1996 VEHICLES HAVE BEEN AVAILABLE IN THE DEALERSHIPS/RETAIL FACILITIES. THE TECHLINE CD-ROM TITLED DISC 13 CONTAINS THE SOFTWARE NEEDED TO PROGRAM ALL 1996 VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD). SPS Tips 1. BATTERY VOLTAGE SHOULD BE CHECKED. A FULLY CHARGED BATTERY IS NECESSARY BEFORE REPROGRAMMING TAKES PLACE. THE VEHICLE BATTERY SHOULD NOT BE CONNECTED TO A BATTERY CHARGER DURING A PROGRAMMING EVENT INCORRECT VOLTAGE COULD CAUSE PROGRAMMING AND/OR CONTROL MODULE FAILURE. During programming, the control module depends on the battery as its sole source of power. Also during programming, the vehicle's components (i.e. blower motor) are set to a default mode which may be turned on, placing additional draw on the vehicle's battery. If the voltage goes outside the specified range (11 to 14 volts) the controllers and the Techline equipment will stop communicating. If this happens, it could cause the control module to become inoperable and require replacement. 2. CHECK THE INTEGRITY OF THE TECH 1 CABLES, MAKE SURE THEY ARE NOT FRAYED, BROKEN OR TWISTED. Loss of communication for any reason will require additional time in completing the reprogramming event. 3. IF USING A TECH 1, YOUR MASS STORAGE CARTRIDGE (MSC) MUST BE UPDATED TO REFLECT THE MOST CURRENT UPDATE OFFERED ON THE TECHLINE CD-ROM. DISC 13, 1995 WAS THE FIRST CD-ROM THAT HAD REMOTE PROGRAMMING SUPPORT If your MSC is not updated to reflect the current software version on the Techline Terminal, in some situations the software will not be capable of interpreting the information that is requested from the vehicle. 4. T-100 TERMINALS (CAMS) ARE NOT CAPABLE OF PROGRAMMING OBD II VEHICLES THROUGH THE DIRECT METHOD. A TECH 1 MUST BE USED (REMOTE METHOD) WHEN REPROGRAMMING WITH A T-100. The T-100 terminals communicate with vehicles through a DLC (ALDL) card and cable found within the T-100's computer. The DLC (ALDL) card is not capable of communicating at the new baud rate used with OBD II. 5. PROGRAMMING IS NOT NEEDED IF THE CURRENT CALIBRATION IS THE SAME AS THE SELECTED CALIBRATION. 6. IF PROGRAMMING A NEW CONTROL MODULE, YOU MUST REQUEST INFORMATION FROM THE NEW CONTROL MODULE. The security information that is needed for a control module to be programmed is stored in the new control module. The security information must be requested from the control module to be programmed. At that point, the control module can be successfully programmed. This requesting of security information takes place in both the direct and remote methods. The request is automatic when using the direct method. Looking at the calibration stored in the old controller may be helpful in selecting the calibration from the CD-ROM for the new controller. 7. WHEN PROGRAMMING OBD II VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD), A VEHICLE INTERFACE MODULE (VIM) IS REQUIRED. The VIM allows the Tech 1 to communicate with the OBD II vehicles. The VIM is necessary for all other Tech 1 diagnostics on OBD II vehicles. VIMs are no longer on backorder. If you are interested in obtaining additional VIMs, call 1-800-GM-TOOLS and ask for VIM kit part number 7000041. 8. DISCONNECT THE TECH I AND VIM FROM THE VEHICLE BETWEEN RETRIEVING DATA AND PROGRAMMING THE VEHICLE. If the VIM remains powered up after data is requested, a communication problem may result when the reprogramming function is performed. 9. WHEN CONNECTING THE TECH 1 TO A TECHLINE TERMINAL (EXCEPT T-100 CAMS), ALWAYS CONNECT THE FLAT GRAY R5232 CABLE FIRST AND THEN THE POWER ADAPTER. FAILURE TO DO SO COULD RESULT IN A LOSS OF INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4088 STORED ON THE TECH 1. When power is turned on to the Tech 1, it looks for the RS232 connection. If it does not see the connection, the Tech 1 in some cases, will erase the information stored for download. 10. DO NOT DISCONTINUE OR INTERRUPT THE PROGRAM LOADING PROCESS TO THE VEHICLE. This will result in a programming error and could prevent the Electronic Control Module (ECM) from functioning properly. 11. AFTER PROGRAMMING IS COMPLETE, PRESS "EXIT". MAKE SURE THE KEY IS CYCLED OFF FOR APPROXIMATELY 10 SECONDS THEN BACK ON. Some vehicles will lose component settings (PMC/IAC Valve). Cycling the key off two times (Off for 30 seconds, On for 10 then repeat a second time) will allow for resetting of the components. Start the vehicle to ensure programming was successful. FOR CADILLAC VEHICLES ONLY a. DUE TO OTHER MODULES ON THE DATA LINE TRYING TO COMMUNICATE WITH THE ECM DURING PROGRAMMING, SOME COMMUNICATION CODES MAY BE SET After programming is complete, clear any codes and verify they do not reset. b. TO HELP MINIMIZE BATTERY DRAW DURING ECM PROGRAMMING, DISCONNECT THE BLOWER MOTOR (AT THE CONNECTOR, NOT THE FUSE) PRIOR TO PROGRAMMING. When programming is complete, reconnect the blower motor. 12. 1997 VEHICLES REQUIRE REPROGRAMMING BE DONE USING A TECH 2. OBD II vehicle calibration size and complexity will require more memory than the Tech 1 has available. Tech 2 will be an essential tool in the first quarter of 1996 containing limited 1996 applications and updates. 13. STG HAS ISSUED BULLETINS (# 53-65-04 and # 53-65-05 - (SEE CHART EXCERPTED FROM 53-65-05 FOR USE AS A QUICK REFERENCE GUIDE), DEVELOPED QUICK REFERENCE GUIDES (P/N SPSCARD-1 AVAILABLE THROUGH YOUR LOCAL GM TRAINING CENTER), PRODUCED CPT VIDEOS (CPT # 56010.00-B), HAD PULSAT BROADCASTS, AND OFFERS GM TRAINING CENTER CLASSROOM COURSES. As you work through reprogramming, keep the above-mentioned material in mind as resources to assist you if difficulty is encountered. As always, the Techline Customer Support Center (1-800-828-6860 English, 1-800-503-3222 French) is always available to assist the technician with any situation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4089 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4090 SPS/EEPROM Programming 1993 to current Reprogrammable Vehicles Note: If programming a new control module you must request info from the new control module first. Battery voltage should be checked and at full charge before reprogramming takes place. System to be programmed should NOT be connected to a battery charger. Incorrect voltage could cause programming and/or control module failure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Page 4091 PROM - Programmable Read Only Memory: Service Precautions A PROM is a sensitive electronic part and must be handled with care. If the connector terminals (pins) on the bottom of the PROM are exposed, avoid touching them. Pins can be broken easily, and the PROM can be damaged by static electric discharge. Follow these guidelines when replacing a PROM: ^ Disconnect the battery ground cable before removing a PROM. Reconnect the cable after the new PROM is installed. ^ DO NOT try to remove a PROM from its plastic PROM carrier. ^ Note the direction in which the original PROM and its carrier were installed in the ECM, and install the replacement PROM in the same direction. Most PROM's are marked with a notch at one end for orientation. Many PROM's can be installed in a reversed direction, which will destroy the PROM when power is applied. CAUTION: A PROM can be damaged by static electric discharge. Avoid damage as follows: ^ DO NOT remove a PROM from its packing material until you are ready to install it. DO NOT hold a PROM by its pins. ^ Before entering a vehicle to remove or replace a PROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps. ^ Avoid sliding across upholstery or carpeting when removing or installing a PROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing a PROM or installing a new one in its socket in the ECM. ^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic, conductive floormats are also available. ^ For some vehicles, it may be desirable to remove the ECM when replacing the PROM. ^ NOTE: See POWERTRAIN MANAGEMENT / SERVICE PRECAUTIONS / VEHICLE DAMAGE WARNINGS / ELECTRICAL PRECAUTIONS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index PROM - Programmable Read Only Memory: Application and ID Introducing the GM PROM Cross Reference Index This PROM cross reference index provides tables that let you use a PROM identification (ID) code to identify the PROM installed in the engine control module (ECM) on most GM vehicles. The code can be either - or both - the internal "scan ID" code or the external PROM code. From the PROM identification, you can find the part number of the PROM and trace the PROM history to determine if any revised PROM's have been issued to supersede the one in the vehicle. The PROM history for a specific vehicle lists a succession of superseding PROM's ending with the most recent PROM released as a service part for the vehicle. PROM's that were released as service parts and explained in a technical service bulletin (TSB) are listed with a description of why the PROM was issued. In most cases, the applicable TSB also is referenced. This index lists ECM PROM's for the 1980-95 vehicles. It does not contain ID codes and part numbers for all PROM's used in all GM vehicles. NOTE: GM flash PROM's (EEPROM's) can only be updated at GM Dealerships with factory-supplied equipment. These cars will not display a PROM ID. By following the steps outlined below, you can use the PROM index to determine if the problem you are diagnosing can possibly be corrected by installing a revised PROM. The PROM index tables are organized by model year, engine displacement, and engine code (the eighth digit of the Vehicle Identification Number). The table columns are arranged as shown below: Example of Table Column Arrangement SCAN PROM PROM PART SUPERSEDING TSB REFERENCE ID CODE (BCC) NUMBER ID PART NUMBER NUMBER (1) (2) (3) (4) (5) .............................................................................................................................................................. ........................................................................ 9461 8958 AMU 16058955R 8290 01228290 86194 Column 1, SCAN ID: The scan ID is the internal PROM identification number transmitted on the ECM data stream and displayed by the scanner as PROM ID. The PROM records for each year and engine are listed numerically by this scan ID. Column 2, PROM CODE: These are the numbers and letters marked on the top of the PROM itself. The numbers are often referred to as the "external PROM ID." The letters are often called the "broadcast code." Together they are the external PROM code. Column 3, PROM P/N: This is the GM part number for the PROM identified by the codes in columns 1 and 2. Column 4, SUPERSEDING ID PROM PART NUMBER: Use the superseding scan ID to locate the newer PROM in the table. If the scan ID for the superseding PROM is not known, the PROM broadcast code is listed here. If the PROM is superseded by a newer PROM, that part number is listed here. Column 5, TSB REFERENCE NUMBER The TSB NUMBER column identifies the original TSB that released this PROM for service. Whenever possible you should refer to the TSB for additional information before changing a PROM. The bulletin may list other parts that must be installed when the PROM is changed, or it may provide additional troubleshooting information. To find a TSB, see Reading Technical Service Bulletins. See: Reading Technical Service Bulletins This will display all the TSB's for that particular vehicle. EXPANDED FOOTNOTES Here you will find SUPERSEDING SCAN ID, PROM PART NUMBERS, symptoms and additional parts that need to be replaced when servicing the PROM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4094 PROM - Programmable Read Only Memory: Application and ID Introducing the GM PROM Cross Reference Index This PROM cross reference index provides tables that let you use a PROM identification (ID) code to identify the PROM installed in the engine control module (ECM) on most GM vehicles. The code can be either - or both - the internal "scan ID" code or the external PROM code. From the PROM identification, you can find the part number of the PROM and trace the PROM history to determine if any revised PROM's have been issued to supersede the one in the vehicle. The PROM history for a specific vehicle lists a succession of superseding PROM's ending with the most recent PROM released as a service part for the vehicle. PROM's that were released as service parts and explained in a technical service bulletin (TSB) are listed with a description of why the PROM was issued. In most cases, the applicable TSB also is referenced. This index lists ECM PROM's for the 1980-95 vehicles. It does not contain ID codes and part numbers for all PROM's used in all GM vehicles. NOTE: GM flash PROM's (EEPROM's) can only be updated at GM Dealerships with factory-supplied equipment. These cars will not display a PROM ID. By following the steps outlined below, you can use the PROM index to determine if the problem you are diagnosing can possibly be corrected by installing a revised PROM. The PROM index tables are organized by model year, engine displacement, and engine code (the eighth digit of the Vehicle Identification Number). The table columns are arranged as shown below: Example of Table Column Arrangement SCAN PROM PROM PART SUPERSEDING TSB REFERENCE ID CODE (BCC) NUMBER ID PART NUMBER NUMBER (1) (2) (3) (4) (5) .............................................................................................................................................................. ........................................................................ 9461 8958 AMU 16058955R 8290 01228290 86194 Column 1, SCAN ID: The scan ID is the internal PROM identification number transmitted on the ECM data stream and displayed by the scanner as PROM ID. The PROM records for each year and engine are listed numerically by this scan ID. Column 2, PROM CODE: These are the numbers and letters marked on the top of the PROM itself. The numbers are often referred to as the "external PROM ID." The letters are often called the "broadcast code." Together they are the external PROM code. Column 3, PROM P/N: This is the GM part number for the PROM identified by the codes in columns 1 and 2. Column 4, SUPERSEDING ID PROM PART NUMBER: Use the superseding scan ID to locate the newer PROM in the table. If the scan ID for the superseding PROM is not known, the PROM broadcast code is listed here. If the PROM is superseded by a newer PROM, that part number is listed here. Column 5, TSB REFERENCE NUMBER The TSB NUMBER column identifies the original TSB that released this PROM for service. Whenever possible you should refer to the TSB for additional information before changing a PROM. The bulletin may list other parts that must be installed when the PROM is changed, or it may provide additional troubleshooting information. To find a TSB, see Reading Technical Service Bulletins. See: Reading Technical Service Bulletins This will display all the TSB's for that particular vehicle. EXPANDED FOOTNOTES Here you will find SUPERSEDING SCAN ID, PROM PART NUMBERS, symptoms and additional parts that need to be replaced when servicing the PROM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4095 PROM - Programmable Read Only Memory: Application and ID Additional PROM Information New ECM PROMs for GM vehicles may be released for service at any time. The information in this system is accurate to the best of the publisher's knowledge and the publication date of the disk. Before ordering a PROM, consult with a GM parts and service dealer to verify the latest part number information. Scanner PROM ID information for earlier-model vehicles (1980-83) is less complete than for later models. To accurately identify PROM's in earlier vehicles, it may be necessary to check the external PROM code marked on the PROM. General Motors has often recommended that dealership technicians check the PROM history of a vehicle and install the most recent PROM revision before performing other diagnostic operations. Each succeeding PROM revision for a specific vehicle includes all previous revisions. Therefore, whenever you consider changing a PROM, review the entire PROM history to see if any revision covered the current driveability problem. Installing the most recent PROM revision may be impractical however for an independent service facility, particularly if the latest PROM revision does not address the specific driveability problem of the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4096 PROM - Programmable Read Only Memory: Application and ID Additional PROM Information New ECM PROMs for GM vehicles may be released for service at any time. The information in this system is accurate to the best of the publisher's knowledge and the publication date of the disk. Before ordering a PROM, consult with a GM parts and service dealer to verify the latest part number information. Scanner PROM ID information for earlier-model vehicles (1980-83) is less complete than for later models. To accurately identify PROM's in earlier vehicles, it may be necessary to check the external PROM code marked on the PROM. General Motors has often recommended that dealership technicians check the PROM history of a vehicle and install the most recent PROM revision before performing other diagnostic operations. Each succeeding PROM revision for a specific vehicle includes all previous revisions. Therefore, whenever you consider changing a PROM, review the entire PROM history to see if any revision covered the current driveability problem. Installing the most recent PROM revision may be impractical however for an independent service facility, particularly if the latest PROM revision does not address the specific driveability problem of the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4097 PROM - Programmable Read Only Memory: Application and ID PROM/MEMCAL Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4098 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4099 PROM - Programmable Read Only Memory: Application and ID PROM/MEMCAL Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4100 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4101 PROM - Programmable Read Only Memory: Application and ID Reading Technical Service Bulletins Always read any Technical Service Bulletins (TSB's) referenced before replacing a PROM. Service bulletins list parts that must be installed when a PROM is changed, and provide information on trouble codes, troubleshooting and driveability problems for which the PROM was released. To find applicable TSB's: Complete TSB Listing 1. Hold down right mouse button and select "Vehicle" in the "Pull Right Menu". 2. Select the TSB ICON. 3. Select "All Technical Service Bulletins by Number, Date, and Title". 4. Select "Sort by Number", "Sort by Date", or "Sort by Title". 5. Scroll up or down to find the desired TSB. PROM TSB Listing Only 1. Hold down right mouse button and select "Technical Service Bulletins" in the "Pull Right Menu". 2. Select "All Technical Service Bulletins for PROM - Programmable Read Only Memory". 3. Select "Sort by Number", "Sort by Date", or "Sort by Title". 4. Scroll up or down to find the desired TSB. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4102 PROM - Programmable Read Only Memory: Application and ID Reading Technical Service Bulletins Always read any Technical Service Bulletins (TSB's) referenced before replacing a PROM. Service bulletins list parts that must be installed when a PROM is changed, and provide information on trouble codes, troubleshooting and driveability problems for which the PROM was released. To find applicable TSB's: Complete TSB Listing 1. Hold down right mouse button and select "Vehicle" in the "Pull Right Menu". 2. Select the TSB ICON. 3. Select "All Technical Service Bulletins by Number, Date, and Title". 4. Select "Sort by Number", "Sort by Date", or "Sort by Title". 5. Scroll up or down to find the desired TSB. PROM TSB Listing Only 1. Hold down right mouse button and select "Technical Service Bulletins" in the "Pull Right Menu". 2. Select "All Technical Service Bulletins for PROM - Programmable Read Only Memory". 3. Select "Sort by Number", "Sort by Date", or "Sort by Title". 4. Scroll up or down to find the desired TSB. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 PROM - Programmable Read Only Memory: Application and ID Footnotes 1 Thru 50 [1] Also needs EGR P/N 1706739. [2] Also requires EGR P/N 17111295. [3] Requires Throttle Body service P/N 17067142, EGR valve service P/N 17067111, Injector service kit P/N 17067976. [4] Requires Throttle Body service P/N 17067142, EGR valve service P/N 17067107, Injector service kit P/N 17067976. [5] Requires Throttle Body service P/N 17067144, EGR valve service P/N 17067110, Injector service kit P/N 17067976. [6] PROM I.D. 7080 KJ is also acceptable for PROM I.D. 5853 KJ only. Requires Throttle Body service P/N 17067144, EGR valve service P/N 17067108 (FED), 17067144 (CAL), Injector service kit P/N 17067976. [7] Required Throttle Body service P/N 17067142, EGR valve service P/N 17067107 (FED), 17068210 (CAL), Injector service kit P/N 17067976. [8] Requires Throttle Body service P/N 17068019, EGR valve service P/N 17067109, Injector service kit P/N 17067976. [9] For Federal - Use 01226047 (PROM CODE 7654 BKW). For California - Use 01226049 (PROM CODE 7665 BKY). [10] For Federal - Use 01226054. For California - Use 01226056 [11] For Federal - Use 01226055. For California - Use 01226057. [12] For Federal - Use 01226046 (PROM CODE 7648 BKU). For California - Use 01226049 (PROM CODE 7665 BKY). [13] For federal - Use 01226046 (PROM CODE 7648 BKU). For California - Use 01226048 (PROM CODE 7659 BKX). [14] ECM may have been replaced by service ECM P/N 16019710 (1225500). [15] ECM may also be 16018161. ECM may also have been replaced by service ECM P/N 16018000 (1225330). [16] ECM may also be 16018201. ECM may also have been replaced by service ECM P/N 16018000 (1225330). [17] ECM may also be 16018211. ECM may have been replaced by service ECM P/N 16018000 (1225330). [18] ECM may also be 16023761. ECM may have been replaced by service ECM P/N 16018000 (1225330). [19] ECM may also be 16018101. ECM may have been replaced by service ECM P/N 16018000 (1225330). [20] For 2-board ECM only. [21] May need EGR valve P/N 17079563. Original equipment P/N 16029014. [22] Original equipment PROM P/N 16017094, now 16025254 [23] Original equipment PROM P/N 16017224, now 16025264. [24] Also needs EGR valve P/N 17079013. Original equipment PROM P/N 16030034 (PROM ID: BOH). [25] Requires kit P/N 25522748 containing: Wiring harness jumper P/N 12043500, Relay P/N 25522747, Foam P/N 25522723, EGR P/N 17079799. [26] Needs EGR valve P/N 17079818. [27] For (MY7) - Use 01226473 (SCAN I.D. = 3941). For (M19) - Use 01226474 (SCAN I.D. = 3951). [28] For (MY7) or (M19, C60) - Use 01226473 (SCAN I.D. = 3941). For (M19) - Use 01226474 (SCAN I.D. = 3951). [29] ECM may also be 16023561(M5), or 16033061(M4 with A/C). [30] For F62 axle - Use 01226441 (SCAN I.D. = 3622). For F17 axle - Use 01226439 (SCAN I.D. = 3332). [31] For one_board ECM only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4105 [32] Requires Thermac Sensor P/N 8997916. [33] For Federal - Use 01227729 (SCAN I.D. = 7729). For California - Use 01227728 (SCAN I.D. = 7728). [34] Use 01227629 (SCAN I.D. = 7629) only to resolve surge or chuggle. [35] Use 01227381 (SCAN I.D. = 7381) only to resolve chuggle. [36] Use 01227386 (SCAN I.D. = 7386) only to resolve chuggle. [37] Retrofit PROM - Does not supersede the regular replacement service PROM. To be used only as required to resolve cases of chuggle. [38] Retrofit PROM - Supersedes all previous service PROM part numbers. To be used as both the regular service replacement (PROM-damaged or defective), and to resolve cases of chuggle. [39] Retrofit PROM - Supersedes all previous service PROM part numbers. To be used as both the regular service replacement (PROM-damaged or defective), and to resolve cases of chuggle, detonation, or flatness. [40] Retrofit PROM - Does not supersede the regular replacement service PROMS. To be used only as required to resolve cases of chuggle, detonation, or flatness. [41] Need EGR valve P/N 17111577 (Federal only). [42] For use with P215/65 tires - use 01228290 (SCAN I.D. = 8290). For use with P235/60, P245/50 tires - use 01228291 (SCAN I.D. = 8291). [43] For use with P215/65 tires - use 01228292 (SCAN I.D. - 8292). For use with P235/60, P245/50 tires - use 01228293 (SCAN I.D. = 8293). [44] Use 16143570 (SCAN I.D. = 3531) for hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093526). Use 16143459 (SCAN I.D. = 3571) for Code 42, Spark Knock, High Idle. [45] Use 16143455 (SCAN I.D. = 3511) for hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093526). Use 16143453 (SCAN I.D. = 3501) for Code 42, Spark Knock, High Idle. [46] Use 16143575 (SCAN I.D. = 3541) for hot hard restart (Requires Fuel Pump P/N 25115764). Use 16143460 (SCAN I.D. = 3581) for Code 42, Spark Knock, High Idle. [47] Use 16143580 (SCAN I.D. = 3551) for hot hard restart (Requires Fuel Pump P/N 25115764). Use 16143462 (SCAN I.D. = 3591) for Code 42, Spark Knock, High Idle. [48] Use 16143457 (SCAN I.D. = 3521) for hot hard restart (Requires Fuel Pump P/N 25115925, Fuel Sender P/N 25092778). Use 16143466 (SCAN I.D. = 3481) for Code 42, Spark Knock, High Idle. [49] Use 16143452 (SCAN I.D. = 3491) for hot hard restart (Requires Fuel Pump P/N 25115925, Fuel Sender P/N 25092778). Use 16143463 (SCAN I.D. = 3451) for Code 42, Spark Knock, High Idle. [50] Needs air injection service kit (P/N 10115773) and new vehicle emission control label. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4106 PROM - Programmable Read Only Memory: Application and ID Footnotes 51 Thru 100 [51] Must be ordered with service kit P/N 10115773. [52] With this PROM installed, use 1987-88 2.8L speed density engine driveability and emissions manual. [53] PROM update eliminates MAF sensor, replacing it with a speed density system. With a 1990 or earlier primary cartridge, I.D. vehicle on scanner as a 1989 model (VIN = K-1-W). [54] For 2WD use 16120099 (SCAN I.D. = 9941). For 4WD use 16120109 (SCAN I.D. = 9901). [55] For 2.73 (GU2) Axle use 16120077 (SCAN I.D. = 9891). For 3.08 (GU4) Axle use 16120082 (SCAN I.D. = 9901). For 3.42 (GU6) and 3.73 (GT4) Axles use 16120086 (SCAN I.D. = 9911). [56] For 2WD use 16120042 (SCAN I.D. = 9991). For 4WD use 16120129 (SCAN I.D. = 0011). [57] Needs accelerator pump check ball spring P/N 17069583. [58] For false Code 44 on long coast down, use retrofit service PROM 01228486 AAND 1050. For regular service replacement, use PROM 16062797 AAND 2798. [59] For false Code 44 on long coast down, use retrofit service PROM 01228487 AANF 1052. For regular service replacement, use PROM 16062801 AANF 2802. [60] USE 16143545 (SCAN I.D. = 3461) For hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093744). Use 16143465 (SCAN I.D. = 3471) for Code 42, Spark Knock, High Idle. [61] With this PROM installed, use 1987-88 2.8L speed density engine driveability and emissions manual. [62] For use with model C1 Trucks - Use 16121162 (SCAN I.D. = 3511). For use with model C2, K, K2, AND K1000 Trucks - use 16121166 (SCAN I.D. = 3521). [63] Also requires installation of new EGR valve package P/N 17112238 (Contains EGR valve P/N 17090078 and a gasket). [64] Use 16181863 (SCAN I.D. = 0844) for cold start stall. Use 16181859 (SCAN I.D. = 0834) only if required to solve both cold start stall and chuggle. [65] Use 16181871 (SCAN I.D. = 0864) for cold start stall. Use 16181867 (SCAN I.D. = 0854) only if required to solve both cold start stall and chuggle. [66] Use 16165848 (SCAN I.D. = 5614) for cold start stall. Use 16165843 (SCAN I.D. = 5624) only if required to solve both cold start stall and chuggle. [67] Do not rely on the scanner ID to determine which PROM is in a vehicle. Look at the BCC on the PROM to be sure. Do not confuse with some 1991 models with a 2.84 axle ratio and a Federal emissions pkg which used scanner ID 5644 but had a BCC of AWJD. [68] This PROM may have a negative impact on fuel economy. [69] Cannot be used on vehicles that do not have digital EGR valves. [70] Use 16165839 (SCAN I.D. = 5634) for cold start stall. Use 16165829 (SCAN I.D. = 5644) only if required to solve both cold start stall and chuggle. [71] Use 16181883 (SCAN I.D. = 0894) for cold start stall. Use 16181875 (SCAN I.D. = 0874) only if required to solve both cold start stall and chuggle. [72] Use 16181887 (SCAN I.D. = 0904) for cold start stall. Use 16181879 (SCAN I.D. = 0884) only if required to solve both cold start stall and chuggle. [73] This PROM may have a negative impact on fuel economy. [74] PROM can only be used with ECM P/N 16144288. [75] Make certain the vehicle has been updated with previously attempted service fixes as follows: EGR valve P/N 17090156 (stamped on valve) 17112373 (GMSPO kit), PCV valve P/N 25098542, ESC module P/N 16175099 (BCC=BARC). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4107 [76] For vehicles with sleeve bearing engines. [77] Combination detonation and neutral gear rattle PROM available. [78] Needs ESC P/N 16175099. [79] Model 2DDM Transmissions - Check dealer records to see if the torque converter has already been replaced with P/N 8650935 (Tagged BCC: DGAF). Trans. with torque converters with P/N 8656959 (Tagged BCC: DG5F) need to replace it with P/N 8650935. [80] For dedicated natural gas vehicles. Order with kit P/N 12545589 unless the only problem is idle fluctuation. [81] For chuggle at 40-45 condition, use PROM only. For tip-in hesitation only, use EGR valve only - P/N 17078431. For cold driveability hesitation, use both PROM and EGR. [82] Requires supplementary tune-up label, spark bypass relay kit P/N 14086983, spark plugs P/N 5614009, sun visor starting label P/N 14085150. Also, remove and discard fuse labeled "crank" from fuse BLK #2 position (3 Amp. Fuse). [83] Manual transmission cars should also be updated with the clutch anticipate switch per dealer service bulletin number. 91-472-7C. [84] Cold driveability, use with PROM 0051 AAF (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [85] Cold driveability, use with PROM 0050 AAF (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [86] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5884 BH (G057). REQUIRES THROTTLE BODY SERVICE P/N 17068019, EGR VALVE SERVICE P/N 17067109, INJECTOR SERVICE KIT P/N 17067976. [87] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5869 BH (G057). REQUIRES THROTTLE BODY SERVICE P/N 17068019, EGR VALVE SERVICE P/N 17067109, INJECTOR SERVICE KIT P/N 17067976. [88] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5779 KB (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067110, INJECTOR SERVICE KIT P/N 17067976. [89] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5778 KB (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067110, INJECTOR SERVICE KIT P/N 17067976. [90] Cold driveability, use with PROM 5854 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [91] Cold driveability, use with PROM 5853 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [92] Cold driveability, use with PROM 5861 KK (G057). REQUIRED THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [93] Cold driveability, use with PROM 5860 KK (G057). REQUIRED THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [94] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5786 LW (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107, INJECTOR SERVICE KIT P/N 17067976. [95] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5785 LW (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107, INJECTOR SERVICE KIT P/N 17067976. [96] Cold driveability, use with PROM 7088 LY (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [97] Cold driveability, use with PROM 7087 LY (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [98] Chuggle at 40-45 mph, cold driveability hesitation. FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4108 [99] Driveability correction for heavy chuggle. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [100] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4109 PROM - Programmable Read Only Memory: Application and ID Footnotes 101 Thru 150 [101] Driveability correction for heavy chuggle. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [102] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [103] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [104] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [105] Surge. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROM. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE. [106] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [107] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [108] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [109] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [110] Surge. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [111] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [112] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [113] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [114] Surge, flatness or tip-in hesitation. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROMS. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [115] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [116] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [117] Spark knock only. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [118] Spark knock only. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [119] Spark knock. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [120] Detonation. USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4110 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [121] Stall, sags, hesitation. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [122] USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [123] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [124] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [125] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [126] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [127] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [128] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [129] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [130] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [131] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [132] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WITH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [133] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [134] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on clutch operation, with manual transmission equipped vehicle. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [135] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [136] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [137] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [138] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [139] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4111 [140] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [141] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [142] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [143] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [144] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [145] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [146] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [147] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [148] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [149] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [150] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4112 PROM - Programmable Read Only Memory: Application and ID Footnotes 151 Thru 200 [151] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [152] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [153] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2WD USE 16120099 (SCAN I.D. = 9941). FOR 4WD USE 16120109 (SCAN I.D. = 9901). [154] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2.73 (GU2) AXLE USE 16120077 (SCAN I.D. = 9891). FOR 3.08 (GU4) AXLE USE 16120082 (SCAN I.D. = 9901). FOR 3.42 (GU6) AND 3.73 (GT4) AXLES USE 16120086 (SCAN I.D. = 9911). [155] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2WD USE 16120042 (SCAN I.D. = 9991). FOR 4WD USE 16120129 (SCAN I.D. = 0011). [156] Prom calibration. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228486 AAND 1050. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062797 AAND 2798. [157] FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228487 AANF 1052. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062801 AANF 2802. [158] Spark knock only. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [159] Spark knock only. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [160] Detonation. USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [161] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [162] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [163] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [164] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [165] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [166] Hard start when hot and detonation. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [167] Hard start when hot and detonation. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [168] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [169] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [170] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4113 [171] Engine stall and/or hesitation after cold start. MUST BE ORDERED WITH SERVICE KIT P/N 10115773. [172] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [173] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [174] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [175] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [176] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [177] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [178] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [179] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [180] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [181] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [182] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [183] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [184] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [185] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [186] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [187] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [188] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4114 DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [189] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [190] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [191] Information on PROM calibrations. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [192] Information on PROM calibrations. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [193] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [194] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [195] FOR USE WITH MODEL C1 TRUCKS - USE 16121162 (SCAN I.D. = 3511). FOR USE WITH MODEL C2, K, K2, AND K1000 TRUCKS USE 16121166 (SCAN I.D. = 3521). [196] Engine surge. ALSO REQUIRES INSTALLATION OF NEW EGR VALVE PACKAGE P/N 17112238 (CONTAINS EGR VALVE P/N 17090078 AND A GASKET). [197] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [198] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [199] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [200] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4115 PROM - Programmable Read Only Memory: Application and ID Footnotes 201 Thru 250 [201] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [202] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [203] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [204] Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [205] Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [206] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [207] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [208] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [209] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [210] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [211] Engine stall, long cranks/idle/decel/surge. CANNOT BE USED ON VEHICLES THAT DO NOT HAVE DIGITAL EGR VALVES. [212] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [213] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [214] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [215] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [216] Cold start extended crank. Engine starts with ignition key cycled. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [217] Cold start extended crank, engine starts with ignition key cycled. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [218] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [219] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [220] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [221] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4116 [222] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. [223] Engine stall. MANUAL TRANSMISSION CARS SHOULD ALSO BE UPDATED WITH THE CLUTCH ANTICIPATE SWITCH PER DEALER SERVICE BULLETIN NO. 91-472-7C. [224] USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [225] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [226] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [227] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [228] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [229] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [230] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. [231] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [232] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [233] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [234] Driveablity improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [235] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [236] Center Port Fuel Injection noise. FOR VEHICLES WITH SLEEVE BEARING ENGINES. [237] Neutral gear rattle only. COMBINATION DETONATION AND NEUTRAL GEAR RATTLE PROM AVAILABLE. [238] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [239] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [240] Unstable idle in park or neutral/poor driveability. FOR DEDICATED NATURAL GAS VEHICLES. ORDER WITH KIT P/N 12545589 UNLESS THE ONLY PROBLEM IS IDLE FLUCTUATION. [241] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [242] Information on PROM calibrations. CANNOT BE USED ON VEHICLES THAT DO NOT HAVE DIGITAL EGR VALVES. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4117 [243] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [244] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [245] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [246] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [247] Check engine light comes on while idling on vehicles equipped with Computer Controlled Emission System (C.C.E.S.), driven in altitudes above 3000 feet. [248] Engine may stop running during parking maneuver or during coast down at low speeds during ambient temperature above 85°F. [249] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [250] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4118 PROM - Programmable Read Only Memory: Application and ID Footnotes 251 Thru 300 [251] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle drive away, or TCC chuggle. [252] Cold start-stall, hesitation, or sag when the engine coolant is between 36°F to 111°F (2°C to 44°C); or Inadequate AC performance when driving at a steady speed and throttle position, between 24 to 64 MPH, when the cruise control is not being used. [253] Lack of throttle response on trucks equipped with governors; or hot restart driveaway sag, both governor and non-governor trucks. [254] Intermittent stall after cold start; engine stalling on coast down; hesitation cold; or ECM CODES E22,E26,E32,E55,E70, and/or E85 [255] PROM I.D. 7080 KJ is also acceptable for PROM I.D. 5853 KJ only. Requires Throttle body service P/N 17067144, EGR valve] service P/N 17067108 (FED), 17067144 (CAL), Injector service kit P/N 17067976. [256] Requires Throttle body service P/N 17067142, EGR valve service P/N 17067107 (FED), 17068210 (CAL), Injector service kit P/N 17067976. [257] FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. [258] REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 015 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 015 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [259] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [260] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [261] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [262] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY AT TEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [263] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [264] MODEL 2DDM TRANS. CARS - CHECK DLR. RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH PN 8650935 (BCC: DGAF). TRANSMISSIONS WITH TORQUE CONVERTERS WITH PN 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED W [265] MODEL 2DDM TRANS. CARS - CHECK DLR. RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH PN 8650935 (BCC: DGAF). TRANSMISSIONS WITH TORQUE CONVERTERS WITH PN 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED W [266] Vehicles equipped with Computer Controlled Emission System (C.C.E.S) experience a Check Engine Light coming on while idling, usually when idling time exceeds 2 minutes with transmission in gear in altitudes above 3000 feet. [267] Cold driveability, use with PROM 5854 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [268] Cold driveability, use with PROM 5853 KJ (G057). PROM I.D. 7079 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5854 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [269] Cold driveability, use with PROM 5861 KK (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4119 [270] Cold driveability, use with PROM 5860 KK (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [271] Tip-in hesitation, lack low speed performance. Used with Manual transaxle vehicles with A/C only. Requires EGR TVS P/N 373510, and A.I.R. valve P/N 17082701. [272] Weak drive-away after cold start, requires EGR TVS P/N 373510. Also, for CALIFORNIA emissions, manual transaxle, replace A.I.R. management valve with PN 17082701. [273] Level road surge, tip-in hesitation, lack of low speed performance - for automatic transaxles only. (Requires EGR valve P/N 17068212). FOR FEDERAL - USE 01226055. FOR CALIFORNIA - USE 01226057. [274] Stall in coast down with clutch disengaged and A/C on, weak drive away after cold start , requires EGR TVS P/N 373510. Also, for CALIFORNIA emissions, manual transaxle, replace A.I.R. management valve with PN 17082701. [275] Idle shake, detonation (G043). FOR 2.5L EFI, AUTOMATIC TRANSAXLE, AND FIRST DESIGN (3-BOARD) ECM. THE SECOND DESIGN (2-BOARD) ECM HAS THE SPARK REVISION ALREADY INCORPORATED IN ITS PROM. [276] Chuggle/surge at 40-45 MPH, tip-in hesitation/sag, spark knock, requires EGR valve (G032). FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. [277] Chuggle and surge at 35-55 MPH, requires EGR kit. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [278] CODE 42, spark knock, cold startability, plug fouling (G040). REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [279] Chuggle and surge at 35-55 MPH, requires EGR kit (G040). REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [280] Cold hesitation/sag, warm surge (G082). RETROFIT PROM SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OF DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [281] TCC chuggle or surge (G043). WHEN INSTALLING PROM IN A CANADIAN 1985 NB, A CODE 13 WILL OCCUR AS THE VEHICLE WAS NOT EQUIPPED WITH AN O2 SENSOR. TO ELIMINATE THE CODE 13, NEED TO INSTALL O2 SENSOR # 8990741 AND CONNECT TO THE EXISTING PURPLE WIRE AND CONNECTOR IN THE [282] Surge or chuggle at 52-60 MPH (G071). RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROM. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE. [283] Surge or chuggle at 52-60 MPH (G071). RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [284] Chuggle, hesitation, tip-in spark knock. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [285] Chuggle, hesitation, tip-in spark knock. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROMS. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [286] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [287] FOR USE WITH P215/65 TIRES - USE 01228292 (SCAN I.D. = 8292). FOR USE WITH P235/60, P245/50 TIRES - USE 01228293 (SCAN I.D. = 8293). [288] FALSE CODES 33, 34, 43, rough idle, chuggle, hesitation (G006,G007). USED WITH VIN #119016 OR LATER ALUMINUM HEAD CORVETTES AND ALL CONVERTIBLE MODELS WITH AUTOMATIC TRANSMISSION, 2.59 (GM1) AXLE ONLY. [289] FALSE CODES 33, 34, 43, rough idle, chuggle, hesitation (G006,G007). USED FOR VIN #119016 OR LATER ALUMINUM HAED CORVETTES AND ALL CONVERTIBLE MODELS WITH AUTOMATIC TRANSMISSION, 2.73 (GU2)/3.07 (G44) AXLE ONLY. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4120 [290] Spark knock. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [291] Spark knock. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [292] Spark knock (G055). USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [293] Spark knock (G043). USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [294] Stalling, tip-in hesitation/sag, rough idle, cold driveability. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [295] Hard hot restart (requires rubber bumper pkg PN 25004553, and a pulsator package PN 25094266), or CODE 42, intermittent high idle, spark knock (G055). [296] USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [297] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [298] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [299] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [300] Spark knock. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4121 PROM - Programmable Read Only Memory: Application and ID Footnotes 301 Thru 350 [301] Spark knock. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [302] Hard start hot (requires installation of a rubber bumper pkg PN 25004553, and a pulsator pkg PN 25094266) or CODE 42, high idle, spark knock (G055). [303] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [304] Hard hot restart (requires rubber bumper pkg PN 25004553, and a pulsator package PN 25094266), or CODE 42, intermittent high idle, spark knock (G055). [305] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [306] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [307] CODES 23, 25, 33, 34, driveability and stalling (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [308] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [309] Code 23, 25, 33, 34, driveability and stalling. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [310] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [311] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 [312] FALSE CODES 43, 54, unstable idle. FOR 2.73 (GU2) AXLE USE 16120077 (SCAN I.D. = 9891). FOR 3.08 (GU4) AXLE USE 16120082 (SCAN I.D. = 9901). FOR 3.42 (GU6) AND 3.73 (GT4) AXLES USE 16120086 (SCAN I.D. = 9911). [313] Running change. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228486 SCAN I.D. 8486, AAND 1050. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062797 SCAN I.D. 2223, AAND 2798. [314] Running change. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228487 SCAN I.D. 8487, AANF 1052. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062801 SCAN I.D. 2233, AANF 2802. [315] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load (G052). [316] Spark knock. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [317] Spark knock. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [318] Spark knock (G043). USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [319] Spark knock (G055). USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [320] CODE 42, spark knock, intermittent high idle. IF MAJOR CONDITION IS HARD HOT ENGINE RESTART, PROM ALSO REQUIRES INSTALLATION OF A RUBBER BUMPER PKG PN 25004553, AND PULSATOR PKG PN 25094266. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4122 [321] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [322] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [323] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [324] Spark knock. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [325] Spark knock. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [326] Tip-in hesitation, stall, CODES 23, 25, 33, or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [327] CODES 23, 25, 33, 34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [328] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/ man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [329] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/ man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [330] CODES 23, 25, 33, 34, driveability and stalling (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [331] Code 23, 25, 33, 34, driveability and stalling. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [332] FOR USE WITH MODEL C1 TRUCKS - USE 16121162 (SCAN I.D. = 3511). FOR USE WITH MODEL C2, K, K2, AND K1000 TRUCKS USE 16121166 (SCAN I.D. = 3521). [333] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load (G052). [334] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [335] [Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [336] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A] [337] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [338] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [339] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [340] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4123 [341] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle driveaway, or TCC chuggle. [342] Cold start-stall, hesitation, or sag when the engine coolant is between 36°F - 111°F (2°C 44°C); or Inadequate A/C performance when driving at steady speed and throttle position, between 24 - 64 MPH, when the cruise control is not being used. [343] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A [344] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [345] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [346] Cold engine extended crank. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [347] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [348] Service Engine Soon light (SES) with a code 43 or tip-in sag, tip-in hesitation, surge at WOT, or spark detonation when cold. [349] Engine stall. MANUAL TRANSMISSION CARS SHOULD ALSO BE UPDATED WITH THE CLUTCH ANTICIPATE SWITCH PER DEALER SERVICE BULLETIN NO. 91-472-7C. [350] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4124 PROM - Programmable Read Only Memory: Application and ID Footnotes 351 Thru 400 [351] USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [352] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [353] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [354] Lack of throttle response on trucks equipped with governors; or hot restart driveaway sag, both governor and non-governor trucks. [355] Low speed driveability or detonation. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [356] Tip-in hesitation, sag, backfire, spark knock. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [357] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle driveaway, or TCC chuggle. [358] Sustained detonation/knock. AUTOMATIC TRANSMISSIONS REQUIRE TORQUE CONVERTER CLUTCH (TCC) CALIBRATION. USE OF THIS PROM IN A NON-DETONATING ENGINE MAY RESULT IN DEGRADED DRIVEABILITY. [359] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 [360] Neutral gear rattle. MAY ALSO REQUIRE CLUTCH DRIVEN PLATE P/N 15961141, AND CLUTCH PILOT BEARING P/N 14061685. COMBINATION DETONATION AND NEUTRAL GEAR RATTLE PROM AVAILABLE. [361] Malfunction Indicator Lamp (check engine light) illuminates and may set a DTC 24 (VSS Circuit Fault) during a California State Emissions Test. [362] Higher than normal hydrocarbon emissions during the idle portion of the inspection and maintenance test. Also, may exhibit a slight detonation during a light throttle acceleration [363] TCC chuggle. MODEL 2DDM TRANS. - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS BEEN REPLACED WITH P/N 8650935 (BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED WITH P/N 8650935. [364] Cold start stall, cold tip in hesitation and/or a cold rough idle after extended idling. Additionally, in 40-50°F ambient temp., fogging on the inside of the front windshield which does not clear with the defroster on occurs. [365] Poor throttle response, stall, misfire, poor cold or hot start, extended crank of the starter with a hot engine, and/or vehicle will start and then stall when the engine is hot. MT vehicles may also experience decel. stall and poor accel. performance. [366] Poor throttle response, stalling, misfire, poor cold or hot starting, extended cranking of the starter with a hot engine, and/or vehicle will start and then stall when the engine is hot. USED WITH MANUAL TRANSMISSION ONLY. [367] MIL illuminates and/or store a DTC 32 (EGR error) with no noticeable driveability concern, usually occurring while climbing a grade. [368] MIL illuminates and/or store a DTC 32 (EGR error) with no noticeable driveability concern, usually occurring while climbing a grade, towing a trailer or driving into a strong head wind. [369] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Page 4125 Prom Information Scan Prom Prom Prom Superseding ID Code Bcc Part # ID Part # TSB Reference # 0375 0369 BMTA 16210369 0825 0820 BKFK 16200819 Running change. 4005 4008 BKZM 16204004 Chevrolet 476501 DTC 32. GMC Truck 476501 4565 4570 BHCN 16194569 4575 4573 BHCP 16194572 6605 6533 BHYZ 16196532 Running change. 6905 6856 BJAY 16196854 6985 6887 BJBB 16196884 6995 6892 BJBC 16196890 7465 7466 BJFC 16197464 Running change. 7475 7469 BJFD 16197468 7735 7737 BJHW 16197736 8085 8053 BJLA 16198052 8095 8057 BJLB 16198056 8105 8060 BJLC 16198059 0825 16200819 8371 9367 AYXY 16169366 8465 8494 BDSD 16188493 8475 8511 BDSF 16188510 8535 8642 BDSN 16188640 6605 16196532 8561 9452 AYYX 16169450 8581 9460 AYYZ 16169459 9295 9308 BDWZ 16189307 9305 9312 BDXA 16189310 9335 9324 BDXD 16189323 9365 9336 BDXJ 16189334 9375 9339 BDXK 16189338 9425 9358 BDXR 16189357 9435 9362 BDXS 16189360 7465 16197464 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Page 4126 9525 9527 BDYT 16189526 9545 9537 BDYW 16189536 9555 9540 BDYX 16189539 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK PROM - Programmable Read Only Memory: Description and Operation CALPAK CAUTION: If the computer is found to be defective and needs replacement, remove the old CALPAK and PROM, then place both into the replacement computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The resistor network calibration called a CALPAK is located inside the computer. Its appearance and service is similar to the PROM. The CALPAK allows fuel to be delivered if other parts of the computer fail. The CALPAK provides the computer with calibrations for: ^ Cold Start Cranking. ^ Limp home fuel (fuel backup mode). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4129 PROM - Programmable Read Only Memory: Description and Operation EEPROM CAUTION: The EEPROM is soldered to the COMPUTER and cannot be serviced separately. Reprogramming of EEPROM information is necessary when replacing a COMPUTER, or when changing the engine and/or transaxle calibrations. Failure to do this will cause the vehicle to have a no start or poor running condition. It is essential that a replacement COMPUTER be reprogrammed with the correct VIN, option content, tire size, and calibration information. Reprogramming of the EEPROM is only possible with the Service Stall System (SSS) hardware available at authorized dealer locations. Check with a dealer before performing COMPUTER replacement or EEPROM reprogramming. DESCRIPTION: The term EEPROM is defined as Electronically Erasable Programmable Read Only Memory (EEPROM) in the COMPUTER. The EEPROM stores vehicle information such as engine and transaxle calibrations, vehicle identification number, programmable vehicle option content and MALF history. Vehicle information stored on the EEPROM has a major effect on how the vehicle will operate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4130 PROM - Programmable Read Only Memory: Description and Operation EPROM CAUTION: The EPROM is serviceable in some applications and can be removed for replacement. If the COMPUTER is found to be defective and needs replacement, remove the old EPROM if applicable and place into the new computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The term EPROM means Erasable Programmable Read Only Memory (EPROM). The EPROM functions in the same manner as a regular PROM and is programmed with data pertaining to the vehicles weight, engine, transmission, axle ratio etc. Automotive technicians do not ERASE or PROGRAM the EPROM in the field. Instead, the EPROM is serviced in one of two manners. Some applications are soldered to the circuit board and require both the computer and EPROM to be replaced as a complete unit. Other applications allow for the EPROM only to replaced. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4131 PROM - Programmable Read Only Memory: Description and Operation MEMCAL CAUTION: If the COMPUTER is found to be defective and needs replacement, remove the old MEMCAL and place it into the replacement computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The MEMCAL assembly contains both the functions of the PROM and the CALPAK. Like the PROM, it contains the calibrations needed for a specific vehicle. It also is the fuel back up control for the computer should it become damaged or faulty. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4132 PROM - Programmable Read Only Memory: Description and Operation PROM CAUTION: If the computer is found to be defective and needs replacement, remove the old PROM and place it into the replacement computer. Some ECM's are equipped with another chip called a CALPAK. If the computer is equipped with a CALPAK chip, it will be located next to the PROM and must be transferred along with the PROM. When replacing the computer always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: To allow one type of computer to be used for many different vehicles, a device called a Programable Read Only Memory (PROM) unit is used. The PROM is located inside the computer and has system calibration information based upon the vehicle's axle ratio, engine, transmission, weight, and other specific configurations of the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > Page 4133 PROM - Programmable Read Only Memory: Testing and Inspection Some control modules may have problems due to cracked solder joints on the circuit board. These internal control module problems can cause the following symptoms: ^ Failure to start or vehicle is stalling. ^ The "CHECK ENGINE" "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR" light will flash or light up, but no trouble codes will be present. ^ Vehicle instrument panel displays may be inoperative. ^ The control module may or may not communicate with the scanner. ^ Other intermittent driveability problems. Incorrect PROM or MEMCAL removal and replacement can create solder joint problems or aggravate an existing condition. See PROM or MEMCAL INSTALLATION for proper procedures. If a solder joint problem results in a "hard" failure, normal test procedures will usually pinpoint a faulty control module. Many symptoms caused by poor solder joints in the control module result in intermittent problems, but they may be hard to duplicate during troubleshooting. Control modules with solder joint problems are sensitive to heat and vibration. You can check for these internal control module problems in either, or both, of the following ways: ^ Remove the control module from its mounting bracket and extend it on the harness so that you can expose it to the vehicle heater ducts. Alternatively, use the flexible duct to route air from the heater to the control module location. Then run the engine and operate the heater at the "MAX HEAT" position. This exposes the control module to approximately 140°F. ^ With the engine running, tap on the control module several times with your hand or finger tips to simulate vehicle vibration. If the engine stumbles or stalls, the "CHECK ENGINE" "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR" light flashes, or any of the previous symptoms occur, the control module may have bad solder joints on the circuit board. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK PROM - Programmable Read Only Memory: Service and Repair CALPAK 1. Remove ECM from vehicle. 2. Remove ECM access cover. 3. Remove Calibration Pack (CALPAK) using removal tool shown. Grasp the CALPAK carrier on the narrow ends only. Gently rock the carrier from end to end while applying a firm upward force. 4. Inspect the reference end of the CALPAK carrier and carefully set aside. Do not remove the CALPAK from the carrier to confirm CALPAK correctness. The notch in the CALPAK is referenced to the small notch in the carrier. The small notch of the carrier must be aligned with the small notch in the socket. CAUTION: ANY TIME THE CALPAK IS INSTALLED BACKWARDS AND THE IGNITION SWITCH IS TURNED ON, THE CALPAK IS DESTROYED. 5. Install the CALPACK by pressing on the CALPAK carrier until it is firmly seated in the socket. Do not press on the CALPAK, only the carrier. 6. Install ECM access cover. 7. Install ECM and perform a DIAGNOSTIC CIRCUIT CHECK to confirm proper installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4136 PROM - Programmable Read Only Memory: Service and Repair EEPROM CAUTION: The Erasable Programmable Read Only Memory (EEPROM) is a permanent memory that is physically soldered to the circuit boards within the computer. It is not serviceable and should not be removed for replacement. If COMPUTER replacement is performed, reprogramming of the EEPROM will be necessary. Failure to do this will cause the vehicle to have a no start or poor running condition. Reprogramming of the EEPROM is only possible with the Service Stall System (SSS) hardware available at authorized dealer locations. Check with a dealer before performing COMPUTER replacement or EEPROM reprogramming. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4137 PROM - Programmable Read Only Memory: Service and Repair EPROM REMOVAL: ^ DO NOT remove an EPROM from its packing material until you are ready to install it. DO NOT hold an EPROM by its pins. ^ Before entering a vehicle to remove or replace an EPROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps. Avoid sliding across upholstery or carpeting when removing or installing an EPROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing or replacing an EPROM. ^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic conductive floormats are also available. ^ It may be desirable to remove the computer for EPROM replacement. ^ Remove computer access cover. ^ Unlock the locking levers by pressing outward toward the sides of the EPROM. ^ Remove EPROM from its socket INSTALLATION: EPROM/MEM-CAL Unit Installation ^ Install the replacement EPROM in the same direction. ^ VERY GENTLY PRESS down on the ends of the EPROM until the locking levers are rotated toward the sides of the EPROM. ^ NOTE: To avoid Computer damage, do not press on the ends of the EPROM until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the EPROM into its socket. ^ While continuing light pressure on the ends of the EPROM, use your index fingers to press the locking levers inward until they are snapped into place. Listen for the click. ^ Install the access cover on the computer. ^ Perform FUNCTIONAL CHECK Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4138 PROM - Programmable Read Only Memory: Service and Repair MEMCAL CONDITION: When installing a service replacement computer, the use of incorrect MEMCAL installation procedures may cause the computer to fail before it can be installed in the vehicle. This condition may appear as if the computer were defective when shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an updated MEMCAL into the vehicles original equipment computer. CAUSE: Excessive vertical force may be applied to the MEMCAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive vertical force may be generated in two ways. ^ Incorrect MEMCAL installation procedures. ^ Interference between MEMCAL and cover. IMPORTANT CORRECTION: This procedure supersedes any instructions regarding MEMCAL installation dated prior to September 1990. 1. Inspect the MEMCAL to determine if a cork spacer is glued to the top side of the MEMCAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in Computer MEMCAL socket. 3. VERY GENTLY PRESS down on the ends of the MEMCAL until the locking levers are rotated toward the sides of the MEMCAL. NOTE: To avoid computer damage, do not press on the ends of the MEMCAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEMCAL into its socket. 4. While continuing light pressure on the ends of the MEMCAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for the click. 5. Install MEMCAL cover and install computer cover. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4139 PROM - Programmable Read Only Memory: Service and Repair PROM 1. Remove ECM from vehicle. 2. Remove ECM access cover. PROM Removal 3. Remove PROM using the rocker-type PROM removal tool shown. Engage one end of the PROM carrier with the hook end of the tool. Press on the vertical bar end of the tool and rock the engaged end of the PROM carrier up as far as possible. Engage the opposite end of the PROM carrier in the same manner and rock this end up as far as possible. Repeat this process until the PROM carrier and PROM are free of the PROM socket. The PROM carrier with the PROM in it should lift off of the PROM socket easily. 4. Inspect the reference end of the PROM carrier and carefully set aside. Do not remove the PROM from the carrier to confirm PROM correctness. The notch in the PROM is referenced to the small notch in the carrier. The small notch of the carrier must be aligned with the small notch in the socket. CAUTION: ANY TIME THE PROM IS INSTALLED BACKWARDS AND THE IGNITION SWITCH IS TURNED ON, THE PROM IS DESTROYED. 5. Install PROM by pressing on the PROM carrier until it is firmly seated in the socket. Do not press on the PROM, only the carrier. 6. Install ECM access cover. 7. Install ECM and perform a DIAGNOSTIC CIRCUIT CHECK to confirm proper installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations Shift Interlock Solenoid: Locations Steering Column Wiring Steering Column Wiring Inside Steering Column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations > Page 4146 C218A, BTSI Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4151 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4154 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN ^ Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). ^ Filter seal may be stuck in the pump. INSPECT ^ Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4157 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4158 Manual Valve Link Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4159 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with 0-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4160 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). ^ Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4161 Case Checkballs And Filters TOOL REQUIRED: ^ J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. ^ The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. ^ Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). ^ Gasket (47) identified by a "C". Gasket (52) identified by a "V". ^ Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT ^ Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4162 Case Checkballs And Filters Filter Screen - Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4163 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4164 Control Valve Assembly - Legend Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4165 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4166 Manual Valve Link Outside Electrical Connector CLEAN ^ Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT ^ Some valves are under pressure - cover the bores while removing roll pins and retainer clips. ^ Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4167 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN ^ All valves, springs, bushings and control valve body in clean solvent. ^ Dry using compressed air. INSPECT ^ All valves and bushings for: Porosity - Scoring - Nicks - Scratches ^ Springs for damaged or distorted coils. ^ Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE ^ Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). ^ Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). ^ Connect the manual valve link (89) to the inside detent lever (88). ^ Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT ^ Wiring harness connections to electrical components. ^ To correctly hook up the wires, see the wiring diagrams. ^ The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN ^ Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). ^ The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4168 TIGHTEN ^ Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN ^ Torque to 12 Nm (9 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4169 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT ^ Seal (29) is reusable. 4. Filter assembly (31). INSPECT ^ Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4170 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4171 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. ^ Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five 0-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4172 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT ^ Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4173 ^ Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN ^ All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. ^ Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. 2. Pistons for: ^ Seal damage. 3. Springs for: ^ Damaged or distorted coils. 4. Valve body casting and accumulator housing for: ^ Porosity. ^ Cracks. ^ Interconnected passages. ^ Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4174 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4175 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4176 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4177 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4178 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN ^ Control valve assembly and accumulator housing (51) thoroughly in clean solvent. ^ Air dry. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4179 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4180 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4181 CLEAN ^ All components. INSPECT ^ All valves, pistons, springs and seals for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4182 ASSEMBLE ^ Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE ^ Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4183 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: ^ Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4184 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN ^ Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4185 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4186 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. ^ # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4187 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT ^ Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN ^ Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4188 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. ^ Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4189 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN ^ Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Description and Operation Torque Converter Clutch Solenoid: Description and Operation OPERATION: The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two conditions must be met. 1. Internal transmission fluid pressure must be correct. 2. The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. This allows the converter clutch to apply, if the hydraulic pressure is correct. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations Shift Interlock Solenoid: Locations Steering Column Wiring Steering Column Wiring Inside Steering Column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations > Page 4198 C218A, BTSI Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4203 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4206 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN ^ Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). ^ Filter seal may be stuck in the pump. INSPECT ^ Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4209 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4210 Manual Valve Link Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4211 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with 0-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4212 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). ^ Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4213 Case Checkballs And Filters TOOL REQUIRED: ^ J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. ^ The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. ^ Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). ^ Gasket (47) identified by a "C". Gasket (52) identified by a "V". ^ Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT ^ Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4214 Case Checkballs And Filters Filter Screen - Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4215 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4216 Control Valve Assembly - Legend Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4217 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4218 Manual Valve Link Outside Electrical Connector CLEAN ^ Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT ^ Some valves are under pressure - cover the bores while removing roll pins and retainer clips. ^ Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4219 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN ^ All valves, springs, bushings and control valve body in clean solvent. ^ Dry using compressed air. INSPECT ^ All valves and bushings for: Porosity - Scoring - Nicks - Scratches ^ Springs for damaged or distorted coils. ^ Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE ^ Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). ^ Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). ^ Connect the manual valve link (89) to the inside detent lever (88). ^ Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT ^ Wiring harness connections to electrical components. ^ To correctly hook up the wires, see the wiring diagrams. ^ The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN ^ Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). ^ The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4220 TIGHTEN ^ Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN ^ Torque to 12 Nm (9 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4221 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT ^ Seal (29) is reusable. 4. Filter assembly (31). INSPECT ^ Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4222 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4223 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. ^ Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five 0-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4224 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT ^ Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4225 ^ Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN ^ All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. ^ Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. 2. Pistons for: ^ Seal damage. 3. Springs for: ^ Damaged or distorted coils. 4. Valve body casting and accumulator housing for: ^ Porosity. ^ Cracks. ^ Interconnected passages. ^ Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4226 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4227 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4228 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4229 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4230 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN ^ Control valve assembly and accumulator housing (51) thoroughly in clean solvent. ^ Air dry. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4231 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4232 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4233 CLEAN ^ All components. INSPECT ^ All valves, pistons, springs and seals for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4234 ASSEMBLE ^ Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE ^ Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4235 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: ^ Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4236 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN ^ Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4237 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4238 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. ^ # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4239 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT ^ Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN ^ Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4240 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. ^ Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4241 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN ^ Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Description and Operation Torque Converter Clutch Solenoid: Description and Operation OPERATION: The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two conditions must be met. 1. Internal transmission fluid pressure must be correct. 2. The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. This allows the converter clutch to apply, if the hydraulic pressure is correct. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement Accumulator: Technical Service Bulletins A/T - 1-2 Accumulator Piston/Outer Spring Replacement File In Section: 7 - Transmission Bulletin No.: 87-71-74 Date: November, 1998 INFORMATION Subject: 1-2 Accumulator Piston and Outer Spring Replacement Models: 1982-96 Buick Roadmaster 1982-96 Cadillac Brougham, Fleetwood, DeVille 1982-86 Chevrolet Caprice 1982-99 Chevrolet Camaro, Corvette 1982-99 Pontiac Firebird with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) 1982-99 Chevrolet and GMC C/K, M/L, S/T, G Models 1991-99 Oldsmobile Bravada with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) Transmissions built from 1982 through 1999 were built with one of two styles of 1-2 accumulator pistons and outer springs. Important: The 1-2 accumulator pistons and outer springs are not interchangeable. For replacement of the 1-2 accumulator piston and outer spring, remove the 1-2 accumulator assembly and inspect the interior for the presence of either an aluminum or composite (plastic) 1-2 accumulator piston. Design 1 1-2 accumulator assemblies with an aluminum piston and a round wire outer spring, use service package P/N 24204495 (1982-1993) or P/N 24204496 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4249 (1994-1997). Design 2 1-2 accumulator assemblies with a composite (plastic) piston and an ovate wire outer spring, started May 11, 1998 (Julian Date 131), use service package P/N 24214343 (1998-1999). Notice: Failure to follow the above instructions may result in transmission distress. Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4250 Accumulator: Technical Service Bulletins A/T - Accumulator Assembly Service Manual Update Group Ref.: Transmission Bulletin No.: 377143 Date: November, 1993 SERVICE MANUAL UPDATE SUBJECT: SECTION 7A - AUTOMATIC - TRANSMISSION UNIT REPAIR - ACCUMULATOR ASSEMBLY MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND L/M, G VANS 1994 OLDSMOBILE BRAVADA TRANSAXLE APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: New product information for 1994 HYDRA-MATIC 4L60-E transmissions. This information has been updated since publication of the 1994 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4251 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4252 DATE OF PRODUCTION CHANGE: (Figures 1, 2 & 3) Beginning with start of production 1994, HYDRA-MATIC 4L60-E transmissions were built with a new calibration that has two (2) springs in the 1-2 accumulator. The 3-4 accumulator has also changed. Some models do not use a 3-4 accumulator spring. SERVICE MANUAL REFERENCE: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4253 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4254 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4255 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4256 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4257 Update your 1994 Service Manual with the five (5) pages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > Page 4258 Accumulator: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Accumulator Cover To Case ............................................................................................................... ................................................................................. 8 FWD Accumulator Cover To Valve Body ....... .............................................................................................................................................................. ...... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Band Apply Servo, A/T > Component Information > Service and Repair Band Apply Servo: Service and Repair 1. Raise and support vehicle. 2. Remove two oil pan bolts from below servo cover. 3. Install servo cover compressor tool No. J-29714 or equivalent on oil pan flange and depress servo cover. 4. Remove servo cover retaining ring. 5. Remove servo cover and seal ring. 6. Remove servo piston and bore-apply pin assembly. 7. Reverse procedure to install. Whenever any servo parts are replaced, apply-pin length must be checked. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Bell Housing, A/T > Component Information > Specifications Bell Housing: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Bellhousing To Case ........................................................................................................................... ............................................................................... 55 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Brake Switch - TCC > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Brake Switch - TCC > Component Information > Locations > Page 4268 Brake Switch - TCC: Diagrams C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis Case: Technical Service Bulletins A/T - Cracked Case Diagnosis Bulletin No.: 02-07-30-024B Date: August 18, 2005 INFORMATION Subject: Diagnosis of Cracked or Broken Transmission Case Models: 2006 and Prior Cars and Light Duty Trucks 2006 and Prior HUMMER H2 2006 HUMMER H3 2005-2006 Saab 9-7X with 4L60/4L60-E/4L65-E or 4L80-E/4L85-E or Allison(R) Series 1000 Automatic Transmission Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 02-07-30-024A (Section 07 - Transmission/Transaxle). Diagnosing the cause of a cracked or broken transmission case requires additional diagnosis and repair or a repeat failure will occur. A cracked or broken transmission case is most often the result of abnormal external torsional forces acting on the transmission case. If none of the conditions listed below are apparent, an internal transmission component inspection may be required. Repairs of this type may be the result of external damage or abuse for which General Motors is not responsible. They are not the result of defects in materials or workmanship. If in doubt, contact your General Motors Service Representative. The following items should be considered: ^ It is important to inspect the vehicle for signs of an out of line condition, impact damage or foreign material to the following components: - The transmission - The engine mounts - The transmission rear mount and crossmember - Vehicle frame damage that alters the front to rear alignment of the driveshaft - The driveshafts (both front and rear) - The wheels (caked with mud, concrete, etc.) - The tires (roundness, lack of cupping, excessive balance weights) - The transfer case (if the vehicle is 4WD) ^ A worn or damaged driveshaft U-Joint has shown to be a frequent cause of transmission case cracking, especially on vehicles that see extended periods of highway driving. Always inspect the U-joint condition when diagnosing this condition. ^ For driveshaft damage or imbalance, Inspect the driveshafts (both front and rear) for dents, straightness/runout or signs of missing balance weights. Also, inspect for foreign material such as undercoat sprayed on the driveshaft. ^ The driveshaft working angles may be excessive or non-canceling, especially if the vehicle carrying height has been altered (lifted or lowered) or if the frame has been extended or modified. ^ Damaged or worn upper or lower rear control arms or bushings. ^ A rear axle that is not seated in the rear spring properly (leaf spring vehicles). ^ Broken rear springs and or worn leaf spring bushings. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis > Page 4273 In some cases, the customer may not comment about a vibration but it is important to test drive the vehicle while using the electronic vibration analysis tool in an attempt to locate the cause of the torsional vibration. Refer to the Vibration Diagnosis and Correction sub-section of the appropriate Service Manual for more details on diagnosing and correcting vibrations. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis > Page 4274 Case: Technical Service Bulletins A/T - New Low and Reverse Support to Case Retainer Ring GROUP REF.: Transmission BULLETIN NO.: 477104 DATE: March, 1994 SUBJECT: NEW LOW AND REVERSE SUPPORT TO CASE RETAINER RING MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND M/L, G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: (Figure 1) New product information for 1994 HYDRA-MATIC 4L60-E transmissions. An enhanced low and reverse support to case retainer ring (ill. 676) has been released. The new low and reverse support to case retainer ring has been enhanced to contact the case ring groove around the entire ring. This will ultimately improve the retention of the ring. Also, the low and reverse support to case retainer ring must be located with the opening in the five o'clock position as shown in Figure 1. NOTE: The GMC Bulletin No. 367106 Automatic Transmission Service Procedure, will remain in effect for GMC trucks only. DATE OF PRODUCTION CHANGE: On August 08, 1993 the HYDRA-MATIC 4L60-E transmissions were built with the new low and reverse support to case retainer ring. SERVICE PARTS INFORMATION: Parts are expected to be available on February 28, 1994. PART NUMBER PART NAME Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis > Page 4275 24200278 Low and Reverse Support to Case Retainer Ring The new low and reverse support to case retainer ring can also be used for 1982-1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > Page 4276 Case: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Accumulator Cover To Case ............................................................................................................... ................................................................................. 8 Case Extension To Case ................................ .............................................................................................................................................................. ....... 26 Auxiliary Valve Body To Case ................................................................................................ ............................................................................................ 8 Bellhousing To Case ........................... .............................................................................................................................................................. ................. 55 Pump Assembly To Case ............................................................................................. ...................................................................................................... 18 Solenoid Assembly To Case ... .............................................................................................................................................................. .............................. 18 Spacer Plate Support To Case ........................................................................ ...................................................................................................................... 8 Transmission Oil Pan To Case ............................................................................................................................................... .............................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Channel Plate, A/T > Component Information > Technical Service Bulletins > A/T Control - DTC P0756 Diagnostic Tips Channel Plate: Technical Service Bulletins A/T Control - DTC P0756 Diagnostic Tips INFORMATION Bulletin No.: 01-07-30-036H Date: January 29, 2009 Subject: Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start Models: 2009 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70) Supercede: This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle). Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC: ^ This is a performance code. This means that a mechanical malfunction exists. ^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set. ^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips. ^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages. ^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking. It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > Customer Interest: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear Clutch: Customer Interest A/T - No Movement in Drive or 3rd Gear TECHNICAL Bulletin No.: 08-07-30-027 Date: June 04, 2008 Subject: No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly) Models: 1982 - 2005 GM Passenger Cars and Light Duty Trucks 2006 - 2007 Buick Rainier 2006 Cadillac Escalade, Escalade ESV, Escalade EXT 2006 Chevrolet SSR 2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer 2006 GMC Yukon Denali, Yukon Denali XL 2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL 2006 Pontiac GTO 2006 - 2007 HUMMER H2 2006 - 2008 HUMMER H3 2006 - 2008 Saab 9-7X with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70) Condition Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position. Cause This condition may be caused by a damaged forward sprag assembly (642). Correction When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures. If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > Customer Interest: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear > Page 4289 If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure. The notches above each sprag must point up as shown when assembled into the outer race. Bearing Assembly, Input Sun Gear Snap Ring, Overrun Clutch Hub Retaining Hub, Overrun Clutch Wear Plate, Sprag Assembly Retainer and Race Assembly, Sprag Forward Sprag Assembly Retainer Rings, Sprag Assembly Outer Race, Forward Clutch Washer, Thrust (Input Carrier to Race) The following information applies when this sprag is used in 1982-86 transmissions. The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > Customer Interest: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear > Page 4290 interchangeable. Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained). Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 08-07-30-027 > Jun > 08 > A/T No Movement in Drive or 3rd Gear Clutch: All Technical Service Bulletins A/T - No Movement in Drive or 3rd Gear TECHNICAL Bulletin No.: 08-07-30-027 Date: June 04, 2008 Subject: No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly) Models: 1982 - 2005 GM Passenger Cars and Light Duty Trucks 2006 - 2007 Buick Rainier 2006 Cadillac Escalade, Escalade ESV, Escalade EXT 2006 Chevrolet SSR 2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer 2006 GMC Yukon Denali, Yukon Denali XL 2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL 2006 Pontiac GTO 2006 - 2007 HUMMER H2 2006 - 2008 HUMMER H3 2006 - 2008 Saab 9-7X with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70) Condition Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position. Cause This condition may be caused by a damaged forward sprag assembly (642). Correction When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures. If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 08-07-30-027 > Jun > 08 > A/T No Movement in Drive or 3rd Gear > Page 4296 If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure. The notches above each sprag must point up as shown when assembled into the outer race. Bearing Assembly, Input Sun Gear Snap Ring, Overrun Clutch Hub Retaining Hub, Overrun Clutch Wear Plate, Sprag Assembly Retainer and Race Assembly, Sprag Forward Sprag Assembly Retainer Rings, Sprag Assembly Outer Race, Forward Clutch Washer, Thrust (Input Carrier to Race) The following information applies when this sprag is used in 1982-86 transmissions. The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 08-07-30-027 > Jun > 08 > A/T No Movement in Drive or 3rd Gear > Page 4297 interchangeable. Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained). Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 577112A > Sep > 95 > A/T Low/Reverse Clutch Spacer Plate Selection Clutch: All Technical Service Bulletins A/T - Low/Reverse Clutch Spacer Plate Selection File In Section: 7 - Transmission Bulletin No.: 57-71-12A Date: September, 1995 Subject: Section 7 - Lo and Reverse Clutch Spacer Plate Selection Models: 1993-95 Buick Roadmaster 1993-95 Cadillac Fleetwood 1993-95 Chevrolet Camaro, Caprice, Corvette 1993-95 Pontiac Firebird 1993-95 Chevrolet and GMC Truck C/K, S/T; M/L, G Models 1993-94 Oldsmobile Bravada with 4L60/4L60-E Transmission (RPOs M30, MD8) This bulletin is being revised to Include the 4L60 Transmission. Please discard Corporate Bulletin Number 57-71-12 (Section 7 - Transmission). The dimension "D" for the overall height for the lo reverse clutch plates is in error. The correct measurement should be 29.22 to 29.90 mm (1.15 to 1.18 inches). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 577112A > Sep > 95 > A/T Low/Reverse Clutch Spacer Plate Selection > Page 4302 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 577112A > Sep > 95 > A/T Low/Reverse Clutch Spacer Plate Selection > Page 4303 Included are the updated pages for your Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 477105 > Mar > 94 > A/T - New Long Lip Seal Design 3-4 and Forward Clutches Clutch: All Technical Service Bulletins A/T - New Long Lip Seal Design 3-4 and Forward Clutches GROUP REF.: Transmission BULLETIN NO.: 477105 DATE: March, 1994 SUBJECT: NEW LONG LIP SEAL DESIGN 3A AND FORWARD CLUTCHES MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND M/L, G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: (Figure 1) New product information for 1994 HYDRA-MATIC 4L60-E transmissions. New clutch piston seal design. The 3-4 clutch piston outer seal and the forward clutch piston outer seals have been redesigned to include a long lip profile for enhanced sealing. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 477105 > Mar > 94 > A/T - New Long Lip Seal Design 3-4 and Forward Clutches > Page 4308 DATE OF PRODUCTION CHANGE: (Figure 2) Beginning with August 09, 1993, the HYDRA-MATIC 4L60-E transmissions were built with a new 3-4 clutch outer seal (long lip). On September 20,1993 the HYDRA-MATIC 4L60-E transmissions were built with a new forward clutch outer seal (long lip). SERVICE PARTS INFORMATION: The new 3-4 clutch outer seal and forward clutch outer seal should be used when rebuilding transmissions that operate under -25°F or if the 3-4 clutch plates or forward clutch plates exhibit a burnt condition. The long lip seals are interchangeable with the current seals. The new design will replace the current seal in service packages as stock is depleted. To order the long lip seals individually use the following part numbers: PART NUMBER PART NAME 8642138 3-4 Clutch Outer Seal 8686146 Forward Clutch Outer Seal These seals can also be used for 1982-1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. NOTE: The GMC Bulletin No. 367106 Automatic Transmission Service Procedure, will remain in effect for GMC trucks only. Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 661510 > Oct > 96 > Sliding Door - Rattles When Driving Over Bumps Sliding Door: All Technical Service Bulletins Sliding Door - Rattles When Driving Over Bumps File In Section: 10 - Body Bulletin No.: 66-15-10 Date: October, 1996 Subject: Sliding Door Rattles When Driving Over Bumps (Replace Upper Door Locator) Models: 1985-96 Chevrolet and GMC M/L Models Condition An owner may comment about a rattle or chucking noise at the sliding door while driving over rough roads or bumps. Cause The sliding door upper locator ends are hitting against the locator socket on the "B" pillar. Correction Remove the upper locator and replace it with new locator, P/N 15742562. The new locator is slightly shorter to prevent the locator ends from making unwanted contact within the locator socket. Service Procedure Refer to Section 10A1, Door Adjustment, of the appropriate year M/L Service Manual. Parts Information P/N Description Qty 15742562 Locator 1 Parts are currently available from GMSPO. Warranty Information: For vehicles repaired under warranty, use: Labor Operation Labor Time B5000 Use Published Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 761502 > Oct > 95 > Sliding Door - Window Latch May Self-Release Sliding Door: All Technical Service Bulletins Sliding Door - Window Latch May Self-Release File In Section: 10 - Body Bulletin No.: 76-15-02 Date: October, 1995 Subject: Sliding Door Window May Self-Release (Install Washer) Models: 1985-94 Chevrolet and GMC Truck M/L Models This bulletin has been revised to add 1990-94 model years. Previous divisional publication numbers were: Chevrolet 89-73-10 GMC Truck 89-T-06 GM Canada 89-2-117 Condition Some owners may comment that the latch on the sliding door window may self-release when the vehicle is driven over rough roads or when the sliding door is being closed. Cause This condition is due to an incorrect window latch mounting pad surface tolerance. Correction Remove the four latch mounting screws and install a 1-1/2 to 2 mm (maximum thickness, 12.5 mm OD. diameter) washer, Part Number 2436161, or equivalent, between the door and each upper latch screw hole as shown in Figure No. 1. Reinstall the four mounting screws. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 761502 > Oct > 95 > Sliding Door - Window Latch May Self-Release > Page 4318 Parts information P/N Description Qty 2436161 Flat Washer 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time C0482 Install Washer Frt 0.3 hr C0483 Install Washer Rear 0.3 hr Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 761502 > Oct > 95 > Sliding Door - Window Latch May Self-Release > Page 4328 Parts information P/N Description Qty 2436161 Flat Washer 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time C0482 Install Washer Frt 0.3 hr C0483 Install Washer Rear 0.3 hr Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Extension Housing, A/T > Component Information > Specifications Extension Housing: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Case Extension To Case ..................................................................................................................... ................................................................................ 26 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: Technical Service Bulletins A/T - DEXRON(R)-VI Fluid Information INFORMATION Bulletin No.: 04-07-30-037E Date: April 07, 2011 Subject: Release of DEXRON(R)-VI Automatic Transmission Fluid (ATF) Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks 2003-2008 HUMMER H2 2006-2008 HUMMER H3 2005-2007 Saturn Relay 2005 and Prior Saturn L-Series 2005-2007 Saturn ION 2005-2008 Saturn VUE with 4T45-E 2005-2008 Saab 9-7X Except 2008 and Prior Chevrolet Aveo, Equinox Except 2006 and Prior Chevrolet Epica Except 2007 and Prior Chevrolet Optra Except 2008 and Prior Pontiac Torrent, Vibe, Wave Except 2003-2005 Saturn ION with CVT or AF23 Only Except 1991-2002 Saturn S-Series Except 2008 and Prior Saturn VUE with CVT, AF33 or 5AT (MJ7/MJ8) Transmission Only Except 2008 Saturn Astra Attention: DEXRON(R)-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids. Supercede: This bulletin is being revised to update information. Please discard Corporate Bulletin Number 04-07-30-037D (Section 07 - Transmission/Transaxle). MANUAL TRANSMISSIONS / TRANSFER CASES and POWER STEERING The content of this bulletin does not apply to manual transmissions or transfer cases. Any vehicle that previously required DEXRON(R)-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid. Some manual transmissions and transfer cases require a different fluid. Appropriate references should be checked when servicing any of these components. Power Steering Systems should now use P/N 9985010 labeled Power Steering Fluid. Consult the Parts Catalog, Owner's Manual, or Service Information (SI) for fluid recommendations. Some of our customers and/or General Motors dealerships/Saturn Retailers may have some concerns with DEXRON(R)-VI and DEXRON(R)-III Automatic Transmission Fluid (ATF) and transmission warranty claims. DEXRON(R)-VI is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids (except as noted above). Please remember that the clean oil reservoirs of the J-45096 - Flushing and Flow Tester machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI for testing, flushing or filling General Motors transmissions/transaxles (except as noted above). DEXRON(R)-VI can be used in any proportion in past model vehicles equipped with an automatic transmission/transaxle in place of DEXRON(R)-III (i.e. topping off the fluid in the event of a repair or fluid change). DEXRON(R)-VI is also compatible with any former version of DEXRON(R) for use in automatic transmissions/transaxles. DEXRON(R)-VI ATF General Motors Powertrain has upgraded to DEXRON(R)-VI ATF with the start of 2006 vehicle production. Current and prior automatic transmission models that had used DEXRON(R)-III must now only use DEXRON(R)-VI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4336 All 2006 and future model transmissions that use DEXRON(R)-VI are to be serviced ONLY with DEXRON(R)-VI fluid. DEXRON(R)-VI is an improvement over DEXRON(R)-III in the following areas: * These ATF change intervals remain the same as DEXRON(R)-III for the time being. 2006-2008 Transmission Fill and Cooler Flushing Some new applications of the 6L80 six speed transmission will require the use of the J 45096 Flushing and Flow Tester to accomplish transmission fluid fill. The clean oil reservoir of the machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI. Parts Information Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4337 Fluid - A/T: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4338 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4339 Fluid - A/T: Technical Service Bulletins A/T - Dexron IIE Preferred Fluid for All Hydra-matic BULLETIN No.: 9274T60-E-02 CORP. REF. NO.: 177125 DATE: October 1991 TRANSMISSION APPLICATIONS: All TRANSMISSION MODELS: All SUBJECT: Dexron(R)-IIE Automatic Transmission/Transaxle Fluid VEHICLE APPLICATIONS: All Hydra-matic Automatic Transmissions/Transaxles BULLETIN COVERS: General Motors has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON(R)-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmissions/transaxles and will eventually replace DEXRON(R)-II. DEXRON(R)-IIE is acceptable for use whenever DEXRON(R)-II was previously specified. DEXRON(R)-II is acceptable for use when DEXRON(R)-IIE is not available. DEXRON(R)-II and DEXRON(R)-IIE can be used in both electronically and hydraulically controlled transmissions/ transaxles. DEXRON(R)-IIE Advantages Over DEXRON(R)-II: ^ Has better anti-foaming characteristic. ^ Improved high temperature oxidation stability and improved low temperature flow characteristics (low temperature viscosity). ^ DEXRON(R)-IIE and DEXRON(R)-II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON(R)-IIE is back serviceable to 1949 for all General Motors automatic transmissions/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON(R)-IIE. SERVICE PART INFORMATION: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4340 Fluid - A/T: Technical Service Bulletins A/T - DEXRON III Fluid Introduction File In Section: 0 - General Information Bulletin No.: 57-02-01 Date: March, 1995 SERVICE MANUAL UPDATE Subject: Section 0 - General Information - DEXRON(R)-III Transmission Fluid Introduction Models: 1995 and Prior Passenger Cars and Trucks General Motors has phased in a new automatic transmission fluid, DEXRON(R)-III, that does not need replacing under normal service. DEXRON(R)-III is designed to help the transmission deliver the best possible performance under all conditions. Refer to Figure 1. The improvements in DEXRON(R)-III include better friction stability, more high temperature oxidation stability and better material compatibility. DEXRON(R)-III has the same low temperature fluidity as DEXRON(R)-IIE, for better transmission performance in cold weather. DEXRON(R)-IIE and DEXRON(R)-III are fully compatible. DEXRON(R)-III is fully compatible with any General Motors passenger vehicle or light truck with automatic transmission and built since 1949. Dealers should require their supplier to include the DEXRON(R)-III license number on all automatic transmission fluid invoices. Starting February 1, 1994 DEXRON(R)-III was phased into all North American assembly plants. DEXRON(R)-III fluid is available from GMSPO (see fluid numbers below): U.S. 1 Quart 12346143 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4341 1 Gallon 12346144 55 Gallon 12346145 In Canada 1 Liter 10952622 4 Liter 10952623 200 Liter 10952624 The 1995 Automatic Transmission/Transaxle fluid change intervals are the following: (1994 and prior should use the schedules as written in the Owner's Manual.) If the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police car or delivery service. Change the fluid and filter every 50,000 miles (63,000 km). If the vehicle is not used mainly under any of these conditions, the fluid and filter do not require periodic changing for vehicles under 8,600 GVWR. Vehicles over 8,600 GVWR change the fluid and filter every 50,000 miles (83,000 km) regardless of driving conditions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Specifications > Capacity Specifications Fluid - A/T: Capacity Specifications CAPACITIES ....................................................................................................................................... ................................................................ QUARTS Pan Capacity ....................................................................................................................................... .............................................................................. 5.0 Total (Overhaul) Capacity ............................... .............................................................................................................................................................. .. 11.2 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Specifications > Capacity Specifications > Page 4344 Fluid - A/T: Fluid Type Specifications Fluid Type ............................................................................................................................................ ............................................................... Dexron IIE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Specifications > Page 4345 Fluid - A/T: Testing and Inspection Fluid level should be checked at every engine oil change. Frequency of change for transmission fluid is dependent on the type of driving conditions in which the vehicle is used. If the transmission is subjected to severe service such as: use in heavy city traffic when the outside temperature regularly reaches 90°F, use in very hilly or mountainous areas, commercial use such as taxi or delivery service, the fluid should be changed every 15,000 miles when using Dexron II and 50,000 miles when using Dexron III or equivalent. Otherwise, change the fluid every 100,000 miles, using Dexron II, III or equivalent automatic transmission fluid. When checking fluid, ensure vehicle is at operating temperature (190°-200°F), which can be obtained by 15 miles of highway-type driving. After transmission fluid is at operating temperature, use the following procedure to check fluid level: 1. Ensure vehicle is on a level surface, then move gear selector to the Park position. 2. Apply parking brake and block wheels, then allow engine to run at idle speed for three minutes with accessories off. 3. Check fluid level, color and condition. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Service and Repair > Changing Fluid Fluid - A/T: Service and Repair Changing Fluid 1. Raise and support vehicle. 2. Loosen two bolts attaching right side of transmission support to frame rail. 3. Remove two bolts attaching left side transmission support to frame rail. 4. Using suitable transmission jack, support and slightly raise transmission. 5. Slide transmission support rearward enough to access rear oil pan attaching bolts. 6. Place drain pan under transmission oil pan, loosen pan bolts on front of pan, pry carefully with screwdriver to loosen oil pan, and allow fluid to drain. 7. Remove remaining oil pan bolts, oil pan, and gasket. 8. Drain fluid from pan, then clean pan and dry thoroughly with compressed air. 9. Remove oil filter to valve body bolt, then remove filter and gasket, replace with new filter and gasket. 10. Install new gasket on oil pan, then oil pan and attaching bolts. Tighten attaching bolts to specification. 11. Lower vehicle and add five quarts of automatic transmission fluid through filler tube. 12. With selector lever in Park and parking brake applied, start engine and let idle. Do not race engine. 13. Move selector lever through each gear range, then return lever to park. 14. Check fluid, then add additional fluid to bring level between dimples on dipstick. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Service and Repair > Changing Fluid > Page 4348 Fluid - A/T: Service and Repair Adding Fluid to A DRY Transmission 1. Add transmission fluid through filler tube until oil level is between the "ADD" and "HOT" marks on dipstick. 2. Place selector lever in park, depress accelerator to place carburetor on fast idle cam, and move selector lever through each range. Do not race engine. 3. With selector lever in park, engine running at idle (1-3 minutes), and vehicle on level surface, check fluid level and add additional fluid to bring level between dimples on dipstick. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal Fluid Filter - A/T: Technical Service Bulletins A/T - Updated Design Oil Filter Assembly & Seal Group Ref.: Transmission Bulletin No.: 377142A Date: February, 1994 INFORMATION SUBJECT: NEW TRANSMISSION OIL FILTER ASSEMBLY MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K AND S/T TRUCKS 1994 CHEVROLET AND GMC M/L AND G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (M30) THIS BULLETIN IS BEING REVISED TO CLARIFY TRANSMISSION USAGE. PLEASE DISCARD BULLETIN 377142. BULLETIN COVERS: New product information for 1994 HYDRA-MATIC 4L60-E transmissions. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal > Page 4353 DATE OF PRODUCTION CHANGE: (Figure 1 and 2) On August 10, 1993 (Julian Date 222), HYDRA-MATIC 4L60-E transmissions were built with a new filter seal (ill. 71) and transmission oil filter assembly (ill. 72). The previous transmission oil filter assembly and filter seal had an assembly method of installing the seal on the filter neck and then installing the filter in the transmission. When using the new filter seal and transmission oil filter assembly, the filter seal must be installed in the transmission first and then install the transmission oil filter assembly into the transmission. NOTE: The new filter seal and transmission oil filter assembly can be used on all HYDRA-MATIC 4L60-E transmissions 1993-1994. The new filter seal and transmission oil filter assembly cannot be used on any HYDRA-MATIC 4L60 transmission. The new filter seal cannot be used with the old transmission oil filter assembly and the new transmission oil filter assembly cannot be used with the old filter seal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Line/Hose, A/T > Component Information > Specifications Fluid Line/Hose: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Connector Cooler Pipe ........................................................................................................................ ............................................................................... 28 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Specifications Fluid Pan: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Transmission Oil Pan To Case ............................................................................................................ ................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Fluid Pan: Service and Repair 4L60-E Automatic Transmission Removal PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Installation PAN AND FILTER ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4362 Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4363 Fluid Pan: Service and Repair 4L80-E Automatic Transmission Removal PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Installation PAN AND FILTER ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4364 Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4368 Fluid Pressure Sensor/Switch: Locations The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4369 Fluid Pressure Sensor/Switch: Description and Operation Pressure Switch Manifold NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Pressure Switch Manifold (PSM) is a gear range sensing device used by the control module to sense what gear has been selected by the vehicle operator. The PSM is located on the valve body and consists of five pressure switches combined into one unit. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pump, A/T > Component Information > Specifications Fluid Pump: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pump Assembly To Case .................................................................................................................... ............................................................................... 18 Pump Cover To Body ..................................... .............................................................................................................................................................. ..... 18 Solenoid Assembly To Pump ................................................................................................... ............................................................................................ 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Governor, A/T > Component Information > Service and Repair Governor: Service and Repair 1. Raise and support vehicle 2. Remove governor cover from case using extreme care not to damage cover. If cover is damaged, it should be replaced. 3. Remove governor. 4. Reverse procedure to install and check fluid level. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Output Shaft, A/T > Component Information > Technical Service Bulletins > A/T - 2-3 Upshift or 3-2 Downshift Clunk Noise Output Shaft: Technical Service Bulletins A/T - 2-3 Upshift or 3-2 Downshift Clunk Noise INFORMATION Bulletin No.: 01-07-30-042F Date: February 05, 2010 Subject: Information on 2-3 Upshift or 3-2 Downshift Clunk Noise Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X with 4L60-E, 4L65-E or 4L70-E Automatic Transmission (RPOs M30, M32, M70) Supercede: This bulletin is being revised to add the 2010 model year and 4L70E transmission. Please discard Corporate Bulletin Number 01-07-30-042E (Section 07 - Transmission/Transaxle). Important For 2005 model year fullsize utilities and pickups, refer to Corporate Bulletin 05-07-30-012. Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift or a 3-2 downshift. During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due to the additional tolerances in the transfer case. This is a normal condition. No repairs should be attempted. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Relays and Modules A/T > Shift Interlock Relay > Component Information > Locations Shift Interlock Relay: Locations Behind LH side of I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Relays and Modules A/T > Shift Interlock Relay > Component Information > Locations > Page 4384 Shift Interlock Relay: Diagrams C217A, Brake/Transmission Shift Interlock Relay C218A, Brake/Transmission Shift Interlock Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > Customer Interest for Seals and Gaskets: > 467108 > Dec > 94 > A/T - Extension Seal Leaks Seals and Gaskets: Customer Interest A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Technical Service Bulletins for Seals and Gaskets: > 467108 > Dec > 94 > A/T - Extension Seal Leaks Seals and Gaskets: All Technical Service Bulletins A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Technical Service Bulletins for Seals and Gaskets: > Page 4398 Seals and Gaskets: By Symptom Technical Service Bulletin # 467108 Date: 941201 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Technical Service Bulletin # 467108 Date: 941201 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Technical Service Bulletins for Seals and Gaskets: > Page 4399 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Technical Service Bulletin # 467108 Date: 941201 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Technical Service Bulletins for Seals and Gaskets: > Page 4400 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > Page 4401 Seals and Gaskets: Service and Repair 1. Remove driveshaft, and tunnel strap, if equipped. 2. Using suitable tool, pry out lip oil seal. 3. Coat outer casting of new oil seal with suitable sealer and drive into place with seal installer tool No. J-21426 or equivalent. 4. Install tunnel strap if used, then install driveshaft. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Brake Switch - TCC > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Brake Switch - TCC > Component Information > Locations > Page 4406 Brake Switch - TCC: Diagrams C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4410 Fluid Pressure Sensor/Switch: Locations The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4411 Fluid Pressure Sensor/Switch: Description and Operation Pressure Switch Manifold NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Pressure Switch Manifold (PSM) is a gear range sensing device used by the control module to sense what gear has been selected by the vehicle operator. The PSM is located on the valve body and consists of five pressure switches combined into one unit. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4416 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4417 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4418 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4419 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Interlock, A/T > Shift Interlock Relay > Component Information > Locations Shift Interlock Relay: Locations Behind LH side of I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Interlock, A/T > Shift Interlock Relay > Component Information > Locations > Page 4427 Shift Interlock Relay: Diagrams C217A, Brake/Transmission Shift Interlock Relay C218A, Brake/Transmission Shift Interlock Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Interlock, A/T > Shift Interlock Solenoid > Component Information > Locations Shift Interlock Solenoid: Locations Steering Column Wiring Steering Column Wiring Inside Steering Column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Interlock, A/T > Shift Interlock Solenoid > Component Information > Locations > Page 4431 C218A, BTSI Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4436 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4439 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN ^ Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). ^ Filter seal may be stuck in the pump. INSPECT ^ Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4442 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4443 Manual Valve Link Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4444 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with 0-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4445 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). ^ Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4446 Case Checkballs And Filters TOOL REQUIRED: ^ J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. ^ The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. ^ Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). ^ Gasket (47) identified by a "C". Gasket (52) identified by a "V". ^ Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT ^ Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4447 Case Checkballs And Filters Filter Screen - Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4448 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4449 Control Valve Assembly - Legend Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4450 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4451 Manual Valve Link Outside Electrical Connector CLEAN ^ Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT ^ Some valves are under pressure - cover the bores while removing roll pins and retainer clips. ^ Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4452 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN ^ All valves, springs, bushings and control valve body in clean solvent. ^ Dry using compressed air. INSPECT ^ All valves and bushings for: Porosity - Scoring - Nicks - Scratches ^ Springs for damaged or distorted coils. ^ Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE ^ Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). ^ Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). ^ Connect the manual valve link (89) to the inside detent lever (88). ^ Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT ^ Wiring harness connections to electrical components. ^ To correctly hook up the wires, see the wiring diagrams. ^ The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN ^ Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). ^ The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4453 TIGHTEN ^ Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN ^ Torque to 12 Nm (9 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4454 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT ^ Seal (29) is reusable. 4. Filter assembly (31). INSPECT ^ Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4455 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4456 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. ^ Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five 0-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4457 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT ^ Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4458 ^ Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN ^ All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. ^ Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. 2. Pistons for: ^ Seal damage. 3. Springs for: ^ Damaged or distorted coils. 4. Valve body casting and accumulator housing for: ^ Porosity. ^ Cracks. ^ Interconnected passages. ^ Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4459 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4460 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4461 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4462 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4463 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN ^ Control valve assembly and accumulator housing (51) thoroughly in clean solvent. ^ Air dry. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4464 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4465 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4466 CLEAN ^ All components. INSPECT ^ All valves, pistons, springs and seals for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4467 ASSEMBLE ^ Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE ^ Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4468 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: ^ Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4469 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN ^ Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4470 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4471 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. ^ # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4472 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT ^ Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN ^ Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4473 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. ^ Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4474 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN ^ Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power Technical Service Bulletin # 467102 Date: 940501 A/T - No Reverse, Perceived Second Gear Lack of Power Group Ref.: Transmission Bulletin No.: 467102 Date: May 1994 SUBJECT: NO REVERSE, OR PERCEIVED LACK OF POWER (TIE UP) IN 2ND GEAR (SHIFT LINKAGE ADJUSTMENT PROCEDURE) MODELS: 1994 CHEVROLET AND GMC TRUCK S/T, M/L, C/K 1, 2 MODELS 1994 OLDSMOBILE BRAVADA WITH 4L60E AUTOMATIC TRANSMISSION (RPO M30) AND ROD STYLE SHIFT LINKAGE Condition Some owners may experience a loss of reverse or a tie-up (perceived lack of power) in 2nd gear. Inspection of these transmissions often indicates heavy wear and evidence of high heat on the low-reverse clutch and 2-4 band. CAUSE: The transmission shift linkage may be improperly adjusted (the manual valve is not properly positioned in relationship to the "PRNDL" position). This may prevent the low-reverse clutch apply circuit from exhausting after a shift from park or reverse to a forward range. If the low-reverse clutch remains partially applied, a tie-up may occur when the transmission shifts from first to second gear. This could result in low-reverse clutch and 2-4 band failure. Correction The transmission shift linkage must be properly adjusted following repair or replacement of the transmission or if the "PRNDL" indicator does not match the actual transmission range. The following procedure must be followed when adjusting the rod style linkage on a 4L60E equipped vehicle: - S/T models use adjustment procedure # 1 - M/L models use adjustment procedure # 2 - C/K models use adjustment procedure # 3 Adjustment procedure # 1 applies to 1994 S/T vehicles with 4L60E transmission: (Figure 1) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power > Page 4483 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral.) 4. Loosen the bolt (2) in the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure that the shift rod moves freely in the swivel. 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that trans control lever (3) is fully seated in trans lever (5). Hold the rod (1) tightly in the swivel (4). Tighten clamp screw (2) against rod (1) to 25 N-m (18 lbs.ft.). Make sure the rod does not move in the swivel while tightening the screw. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety *switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 2 applies to 1994 M/L vehicles with 4L60E transmission: (Figure 2) 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3), Make sure the rod slides freely in the swivel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power > Page 4484 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that transmission equalizer lever (3) is fully seated in trans lever (5). Hold the shift rod (1) tightly in the swivel (4) and tighten the bolt (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to slide in the swivel while tightening. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 3 applies to 1994 C/K vehicles with 4L60E transmission: (Figure 3) 1. Linkage adjustment must be performed at the lower end of the steering column prior to any "PRNDL" indicator adjustment. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure the rod slides freely in the swivel. 5. Set trans lever (3) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Hold the rod (1) tightly in the swivel (4) and tighten screw (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to move in the swivel while tightening. 7. Verify proper adjustment: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power > Page 4485 - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Please note these new procedures in the appropriate Service Manual, Section 7A. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor 0p Description Labor Time K5244 Linkage, Shift Use Published Adjust Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power Technical Service Bulletin # 467102 Date: 940501 A/T - No Reverse, Perceived Second Gear Lack of Power Group Ref.: Transmission Bulletin No.: 467102 Date: May 1994 SUBJECT: NO REVERSE, OR PERCEIVED LACK OF POWER (TIE UP) IN 2ND GEAR (SHIFT LINKAGE ADJUSTMENT PROCEDURE) MODELS: 1994 CHEVROLET AND GMC TRUCK S/T, M/L, C/K 1, 2 MODELS 1994 OLDSMOBILE BRAVADA WITH 4L60E AUTOMATIC TRANSMISSION (RPO M30) AND ROD STYLE SHIFT LINKAGE Condition Some owners may experience a loss of reverse or a tie-up (perceived lack of power) in 2nd gear. Inspection of these transmissions often indicates heavy wear and evidence of high heat on the low-reverse clutch and 2-4 band. CAUSE: The transmission shift linkage may be improperly adjusted (the manual valve is not properly positioned in relationship to the "PRNDL" position). This may prevent the low-reverse clutch apply circuit from exhausting after a shift from park or reverse to a forward range. If the low-reverse clutch remains partially applied, a tie-up may occur when the transmission shifts from first to second gear. This could result in low-reverse clutch and 2-4 band failure. Correction The transmission shift linkage must be properly adjusted following repair or replacement of the transmission or if the "PRNDL" indicator does not match the actual transmission range. The following procedure must be followed when adjusting the rod style linkage on a 4L60E equipped vehicle: - S/T models use adjustment procedure # 1 - M/L models use adjustment procedure # 2 - C/K models use adjustment procedure # 3 Adjustment procedure # 1 applies to 1994 S/T vehicles with 4L60E transmission: (Figure 1) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power > Page 4491 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral.) 4. Loosen the bolt (2) in the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure that the shift rod moves freely in the swivel. 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that trans control lever (3) is fully seated in trans lever (5). Hold the rod (1) tightly in the swivel (4). Tighten clamp screw (2) against rod (1) to 25 N-m (18 lbs.ft.). Make sure the rod does not move in the swivel while tightening the screw. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety *switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 2 applies to 1994 M/L vehicles with 4L60E transmission: (Figure 2) 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3), Make sure the rod slides freely in the swivel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power > Page 4492 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that transmission equalizer lever (3) is fully seated in trans lever (5). Hold the shift rod (1) tightly in the swivel (4) and tighten the bolt (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to slide in the swivel while tightening. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 3 applies to 1994 C/K vehicles with 4L60E transmission: (Figure 3) 1. Linkage adjustment must be performed at the lower end of the steering column prior to any "PRNDL" indicator adjustment. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure the rod slides freely in the swivel. 5. Set trans lever (3) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Hold the rod (1) tightly in the swivel (4) and tighten screw (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to move in the swivel while tightening. 7. Verify proper adjustment: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power > Page 4493 - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Please note these new procedures in the appropriate Service Manual, Section 7A. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor 0p Description Labor Time K5244 Linkage, Shift Use Published Adjust Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Specifications > Shift Rod Swivel Attaching Nuts Shift Linkage: Specifications Shift Rod Swivel Attaching Nuts Shift Rod Swivel Attaching Nut ............................................................................................................ ................................................................. 11 Ft.Lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Specifications > Shift Rod Swivel Attaching Nuts > Page 4496 Shift Linkage: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Manual Shaft To Inside Detent Lever .................................................................................................. .............................................................................. 23 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Specifications > Page 4497 Shift Linkage: Adjustments Fig.7 Shift Linkage Adjustment 1. Apply parking brake, then loosen swivel nut, Fig. 7. 2. Place column selector lever in neutral. 3. Place transmission in Neutral by moving shift lever to its forward position, then back to the second detent position. 4. Holding shift rod tightly in the swivel, tighten swivel nut to specifications. 5. Place column selector lever into park position and check adjustment. The column selector lever must move through all the detents. The engine must start in the park or Neutral positions. With the selector lever in the park position, the parking pawl should freely engage within the rear (reaction) internal gear lugs or the output ring gear lugs and prevent the vehicle from rolling, which could result in personal injury. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Speedometer Gear, A/T > Component Information > Service and Repair Speedometer Gear, A/T: Service and Repair 1. Disconnect speedometer cable or P.M. generator electrical connector at transmission. 2. Remove retainer bolt, retainer, P.M. generator if equipped, speedometer driven gear and O-ring seal. 3. Reverse procedure to install, using new O-ring and adding fluid as necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > Customer Interest for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear Sun Gear: Customer Interest A/T - 4L60/65E, No Reverse/2nd or 4th Gear TECHNICAL Bulletin No.: 00-07-30-022D Date: June 10, 2008 Subject: No Reverse, Second Gear or Fourth Gear (Replace Reaction Sun Shell with More Robust Heat Treated Parts) Models: 1993 - 2005 GM Passenger Cars and Light Duty Trucks 2003 - 2005 HUMMER H2 with 4L60/65-E Automatic Transmission (RPOs M30 or M32) Supercede: This bulletin is being revised to add 2005 model year to the parts information. Please discard Corporate Bulletin Number 00-07-30-022C (Section 07 - Transmission/Transaxle). Condition Some customers may comment on a no reverse, no second or no fourth gear condition. First and third gears will operate properly. Cause The reaction sun gear (673) may not hold inside the reaction sun shell (670). Correction Important: There are FOUR distinct groups of vehicles and repair procedures involved. Vehicles built in the 2001 model year and prior that make use of a reaction shaft to shell thrust washer: ^ The sun shell can be identified by four square holes used to retain the thrust washer. Use reaction sun shell P/N 24228345, reaction carrier to shell thrust washer (699B) P/N 8642202 and reaction sun gear shell thrust washer (674) P/N 8642331er (674) P/N 8642331along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and prior that have had previous service to the reaction sun shell: It is possible that some 2001 and prior model year vehicles have had previous service to the reaction sun shell. At the time of service, these vehicles may have been updated with a Reaction Sun Shell Kit (Refer to Service Bulletin 020730003) without four square holes to retain the thrust washer. If it is found in a 2001 model year and prior vehicles that the reaction sun shell DOES NOT have four square holes to retain the thrust washer, these vehicles must be serviced with P/Ns 24229825 (674), 24217328 and 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and later that make use of a reaction shaft to shell thrust bearing: The sun shell can be identified by no holes to retain the thrust washer. Use reaction sun shell, P/N 24229825, reaction carrier shaft to shell thrust bearing (669A), P/N 24217328 and reaction sun gear shell thrust washer (674), P/N 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built from November, 2001 through June, 2002: These vehicles should have the reaction carrier shaft replaced when the sun shell is replaced. Use shell kit P/N 24229853, which contains a sun shell (670), a reaction carrier shaft (666), a reaction carrier shaft to shell thrust bearing (669A) and a reaction sun gear shell thrust washer (674). The appropriate seals and washers listed below should also be used. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Follow the service procedure below for diagnosis and correction of the no reverse, no second, no forth condition. Important: If metallic debris is found on the transmission magnet, the transmission must be completely disassembled and cleaned. Metallic debris is defined as broken parts and pieces of internal transmission components. This should not be confused with typical "normal" fine particles found on all transmission magnets. Failure to properly clean the transmission case and internal components may lead to additional repeat repairs. 1. Remove the transmission oil pan and inspect the magnet in the bottom of the pan for metal debris. Refer to SI Document ID # 825141. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > Customer Interest for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 4509 2. Remove the transmission from the vehicle. Refer to the appropriate SI document. Important: ^ Inspect all the transmission components for damage or wear. Replace all damaged or worn components. The parts shown above should be sufficient to correct this concern. ^ This condition does not normally require replacement of the transmission completely. Components such as clutches, valve body, pump and torque converters will NOT require replacement to correct this condition. Disassemble the transmission and replace the appropriate parts listed below. Refer to the Unit Repair Manual - Repair Instructions. 3. Reinstall the transmission in the vehicle. Refer to appropriate service information. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > Customer Interest for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 4510 Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear Sun Gear: All Technical Service Bulletins A/T - 4L60/65E, No Reverse/2nd or 4th Gear TECHNICAL Bulletin No.: 00-07-30-022D Date: June 10, 2008 Subject: No Reverse, Second Gear or Fourth Gear (Replace Reaction Sun Shell with More Robust Heat Treated Parts) Models: 1993 - 2005 GM Passenger Cars and Light Duty Trucks 2003 - 2005 HUMMER H2 with 4L60/65-E Automatic Transmission (RPOs M30 or M32) Supercede: This bulletin is being revised to add 2005 model year to the parts information. Please discard Corporate Bulletin Number 00-07-30-022C (Section 07 - Transmission/Transaxle). Condition Some customers may comment on a no reverse, no second or no fourth gear condition. First and third gears will operate properly. Cause The reaction sun gear (673) may not hold inside the reaction sun shell (670). Correction Important: There are FOUR distinct groups of vehicles and repair procedures involved. Vehicles built in the 2001 model year and prior that make use of a reaction shaft to shell thrust washer: ^ The sun shell can be identified by four square holes used to retain the thrust washer. Use reaction sun shell P/N 24228345, reaction carrier to shell thrust washer (699B) P/N 8642202 and reaction sun gear shell thrust washer (674) P/N 8642331er (674) P/N 8642331along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and prior that have had previous service to the reaction sun shell: It is possible that some 2001 and prior model year vehicles have had previous service to the reaction sun shell. At the time of service, these vehicles may have been updated with a Reaction Sun Shell Kit (Refer to Service Bulletin 020730003) without four square holes to retain the thrust washer. If it is found in a 2001 model year and prior vehicles that the reaction sun shell DOES NOT have four square holes to retain the thrust washer, these vehicles must be serviced with P/Ns 24229825 (674), 24217328 and 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and later that make use of a reaction shaft to shell thrust bearing: The sun shell can be identified by no holes to retain the thrust washer. Use reaction sun shell, P/N 24229825, reaction carrier shaft to shell thrust bearing (669A), P/N 24217328 and reaction sun gear shell thrust washer (674), P/N 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built from November, 2001 through June, 2002: These vehicles should have the reaction carrier shaft replaced when the sun shell is replaced. Use shell kit P/N 24229853, which contains a sun shell (670), a reaction carrier shaft (666), a reaction carrier shaft to shell thrust bearing (669A) and a reaction sun gear shell thrust washer (674). The appropriate seals and washers listed below should also be used. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Follow the service procedure below for diagnosis and correction of the no reverse, no second, no forth condition. Important: If metallic debris is found on the transmission magnet, the transmission must be completely disassembled and cleaned. Metallic debris is defined as broken parts and pieces of internal transmission components. This should not be confused with typical "normal" fine particles found on all transmission magnets. Failure to properly clean the transmission case and internal components may lead to additional repeat repairs. 1. Remove the transmission oil pan and inspect the magnet in the bottom of the pan for metal debris. Refer to SI Document ID # 825141. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 4516 2. Remove the transmission from the vehicle. Refer to the appropriate SI document. Important: ^ Inspect all the transmission components for damage or wear. Replace all damaged or worn components. The parts shown above should be sufficient to correct this concern. ^ This condition does not normally require replacement of the transmission completely. Components such as clutches, valve body, pump and torque converters will NOT require replacement to correct this condition. Disassemble the transmission and replace the appropriate parts listed below. Refer to the Unit Repair Manual - Repair Instructions. 3. Reinstall the transmission in the vehicle. Refer to appropriate service information. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 4517 Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter > Component Information > Technical Service Bulletins > A/T - Torque Converter Replacement Information Torque Converter: Technical Service Bulletins A/T - Torque Converter Replacement Information INFORMATION Bulletin No.: 01-07-30-010C Date: May 12, 2008 Subject: Automatic Transmission/Transaxle Torque Converter Replacement Models: 2009 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saturn Cars and Light Duty Trucks (Except VTi Equipped Vehicles (RPO M16 and M75) 2009 and Prior Saab 9-7X with ALL Automatic Transmissions and Transaxles Supercede: This bulletin is being revised to add the 2007-2009 model years. Please discard Corporate Bulletin Number 01-07-30-010B (Section 07 - Transmission/Transaxle). The purpose of this bulletin is to help technicians determine when a torque converter should be replaced. Below is a list of general guidelines to follow. The converter should NOT be replaced if the following apply: ^ DTC P0742 - TCC stuck on is set. This code is almost always the result of a controls condition (i.e. stuck TCC solenoid/valve). Experience has shown that this code rarely indicates a mechanical concern within the torque converter. ^ The fluid has an odor or is discolored but no evidence of metal contamination. ^ Fine metal particles (traces of metal flakes/gray color to fluid ) are found in the converter. This is not harmful to the torque converter. ^ The vehicle has been exposed to high mileage. ^ A small amount of wear appears on the hub where the oil pump drive gear mates to the converter (RWD only). A certain amount of such wear is normal for both the hub and oil pump gear. Neither the converter nor the front pump assembly should be replaced. The torque converter should be replaced under any of the following conditions: ^ The vehicle has TCC shudder and/or no TCC apply. First complete all electrical and hydraulic diagnosis and check for proper engine operation. The converter clutch may be damaged. Also the converter bushing and/or internal 0-ring may be damaged. ^ Evidence of damage to the oil pump assembly pump shaft turbine shaft drive sprocket support and bearing or metal chips/debris in the converter. ^ Metal chips/debris are found in the converter or when flushing the cooler and the cooler lines. ^ External leaks in the hub weld area lug weld or closure weld. ^ Converter pilot is broken damaged or fits poorly into the crankshaft. ^ The converter hub is scored or damaged. ^ The transmission oil is contaminated with engine coolant engine oil or water. ^ If excessive end play is found after measuring the converter for proper end play (refer to Service Manual). ^ If metal chips/debris are found in the fluid filter or on the magnet and no internal parts in the unit are worn or damaged. This indicates that the material came from the converter. ^ The converter has an unbalanced condition that results in a vibration that cannot be corrected by following Converter Vibration Procedures. ^ Blue converter or dark circular ring between lugs. This condition will also require a complete cleaning of the cooler and a check for adequate flow Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter > Component Information > Technical Service Bulletins > A/T - Torque Converter Replacement Information > Page 4522 through the cooler. ^ Converter bearing noise determined by noise from the bell housing area in Drive or Reverse at idle. The noise is gone in Neutral and Park. ^ If silicon from the viscous clutch is found in the lower pan (4T80-E ONLY). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Description and Operation Torque Converter Clutch Solenoid: Description and Operation OPERATION: The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two conditions must be met. 1. Internal transmission fluid pressure must be correct. 2. The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. This allows the converter clutch to apply, if the hydraulic pressure is correct. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush Transmission Cooler: Technical Service Bulletins A/T - Fluid Oil Cooler Flush INFORMATION Bulletin No.: 02-07-30-052G Date: March 02, 2011 Subject: Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow(R) Models: 2011 and Prior Passenger Cars and Light Duty Trucks 2003-2010 HUMMER H2 2006-2010 HUMMER H3 with Automatic Transmission/Transaxle including Allison(R) Transmissions Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 02-07-30-052F (Section 07 - Transmission/Transaxle). Important All labor operations that include removal of the transmission from the vehicle include labor time to flush the transmission oil cooler system. The J 45096 transmission oil cooling system flush and flow test tool replaces current tool J 35944-A. J 45096 is a self-contained unit utilizing a 12-volt flow meter, shop air supply and DEXRON(R) VI automatic transmission fluid (ATF). In the flush mode, transmission fluid is cycled through the transmission oil cooling system. High-pressure air is automatically injected into the fluid stream adding agitation to the ATF oil to enhance the removal of contaminated ATF oil and debris. In the flow mode, an electronic flow meter is used to measure the flow capability of the ATF oil cooling system. A digital display indicates the ATF oil flow rate in gallons per minute (GPM) along with the amount of ATF oil in the supply vessel, supply vessel ATF oil temperature, machine cycles and the operating mode. The supply oil vessel has 30 L (32 qt) capacity and the waste oil vessel has 32 L (34 qt) capacity. The waste oil vessel is constructed of a translucent composite material that allows the user to easily identify the oil level. The waste oil vessel can accommodate vacuum evacuation and gravity draining. In the code mode, a random, encrypted code is generated that can be used for verification of flow test results. Current essential cooler line adapters are used to connect the J 45096 to the automatic transmission oil cooler lines that allows J 45096 to adapt to General Motors passenger cars and light duty trucks, current and past models (except the Pontiac Vibe, Wave and Chevrolet Aveo). The tool may be adapted for use on the Pontiac Vibe, Wave and Chevrolet Aveo by dealership personnel with a barbed hose connector and rubber hose obtained locally. The Vibe's/Wave's/Aveo's transmission has a transmission oil requirement which is slightly different than DEXRON(R) VI ATF. However, flushing the cooler with DEXRON(R) VI automatic transmission fluid is an acceptable service procedure. Very little fluid remains in the cooler after the flush procedure and the residual DEXRON(R) VI ATF in the cooler is compatible with the Vibe's/Wave's/Aveo's transmission fluid. Notice Insufficient oil flow through the ATF oil cooling system will cause premature transmission failure. The required minimum ATF oil flow rate reading is directly related to the supply oil temperature. Refer to the flow rate reference chart for the oil flow rate specification based on the temperature of the ATF in the supply vessel. Helpful Hints for Maintaining the Temperature at or above 18°C (65°F) Important - The temperature of the supply vessel oil must be 18°C (65°F) or greater for J 45096 to operate. It is recommended to store the J 45096 in an area of the dealership where the room temperature remains at or above 18°C (65°F) when not in use. - Do not attempt to increase the fluid temperature in the Transflow(R) machine with an engine oil dipstick, or any other immersion type heater. The Transflow(R) machine has a check valve in the supply reservoir. Inserting a heater will damage the check valve and the subsequent repair expense would be the dealer's responsibility. - A heater blanket, P/N J-45096-10, is available for the Transflow(R) transmission cooling system flushing tool. This heater fastens around the Transflow(R) internal supply vessel and runs on 110 volts AC. The heater will warm the ATF in the supply vessel to at least 18°C (65° F) and has a thermostat to hold a constant temperature. Store the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine in a room where the temperature is maintained at or above 18°C (65°F). Keep the ATF level in the reservoir low when the Transmission Cooling System Service Tool, J 45096, Transflow(R), is not in use. Store several gallons of oil in an area where the temperature is maintained at or above 18°C (65°F). Fill the reservoir of the J 45096 as needed before using the machine on Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 4530 each repair. With the ATF in a tightly sealed container, place the container in a tub of hot water for a period of time. Then pour the ATF into the reservoir. This method works best with a low fluid level in the reservoir. Place the Transflow(R) machine in the direct sunlight with the cabinet door open to expose the reservoir to the rays of the warm sun. Flush / Flow Test Procedure Important All labor operations that include removal of the transmission from the vehicle and require the transmission oil pan or transmission side cover to be removed include labor time to flush the transmission oil cooler system. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate procedure. Important The J 45096 can be used to flush the transmission oil cooler system on an Allison equipped vehicle, but the flow meter should not be utilized. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate flow check procedure. Machine Displays After completion of the flush and flow test, the following information is to be recorded on the repair order. This information is displayed on the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine when the dial is in the code position. - Tested flow rate (displayed in Gallons Per Minute (GPM) - Temperature (displayed is degrees Fahrenheit) - Cycle number (a number) - Seven digit Alpha/Numeric flow code (i.e. A10DFB2) Warranty Information Important All labor operations that include removal of the transmission from the vehicle include labor time to flush the transmission oil cooler system. Performing a transmission oil cooling system flush and flow test will use between 4.7-7.5 L (5-8 qts) of DEXRON(R)VI transmission fluid. The amount Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 4531 of transmission fluid (ATF), (DEXRON(R)VI) (fluid) that is to be charged for the flush portion of the repair should not exceed the allowable charge for 7.5 L (2 gal) of fluid. This expense should be shown in the Parts Section of the warranty claim document. The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, "MUST" be written on the job card and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim. The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, "MUST" be written on the job card, entered in the warranty claim labor operation Flush Code additional field (when available) and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 4532 Transmission Cooler: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 4533 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 4534 Transmission Cooler: Technical Service Bulletins A/T - Oil Cooler Flushing Frequently Asked Questions File In Section: 07 - Transmission/Transaxle Bulletin No.: 03-07-30-027 Date: June, 2003 INFORMATION Subject: Most Frequently Asked Questions and Answers for J 45096 TransFlow Transmission Oil Cooling System Flushing Machine Models: 2004 and Prior Passenger Cars and Light Duty Trucks with Automatic Transmission/Transaxle 2004 and Prior HUMMER H2 This bulletin is issued to help answer the most frequently asked questions and concerns about essential tool J 45096. Q: Why doesn't the machine work below 18°C (65°F)? A: The flow characteristics of ATF at temperatures below 18°C (65°F) does not provide accurate flow test results with the electronics used in the J 45096. Q: Why didn't the unit come with a tank heater? A: The vast majority of dealerships do not require a heater to keep the ATF above 18°C (65°F). As a result, the heater was deleted as a cost-savings measure. A tank heater, J 45096-10, is currently available from Kent-Moore if your dealership requires it. Refer to Corporate Bulletin Number 03-07-30-002A for suggestions on warming the ATF without using a heater blanket. Q: Why does the machine fail new oil coolers? A: Several reasons have been found. The most likely reason is the air pressure at the air hose connected to the J 45096 is less than 586 kPa (85 psi). Other reasons include a twisted hose inside the J 45096 at the bulkhead as a result of the nut turning when the waste or supply hose was installed, the internal pressure regulator was improperly set at the factory or a problem with the cooler lines on the vehicle. Perform the J 45096 self-test as described on pages 9 and 10 of the Operation Manual. If a problem is still detected, refer to Troubleshooting on page 19 of the Operation Manual. If a problem still persists, contact Kent-Moore Customer Service at 1-800-345-2233. Q: What is the difference between steel and aluminum oil coolers? A: The aluminum oil cooler tube is slightly thinner in construction than the steel oil cooler tube, which affects the oil flow rate. The fitting that is protruding out of the radiator tank easily identifies the aluminum oil cooler. Refer to the Quick Reference card provided with the J 45096 in order to identify the proper flow rate for the aluminum oil cooler. Q: Why can't I use TransFlow for Allison transmission cooling Systems? A: Validation of TransFlow is currently under development for light duty trucks equipped with the Allison automatic transmission. TransFlow is based on the existing MINIMUM flow rate specification through the transmission oil cooling system. The Allison transmission oil cooling system only has MAXIMUM oil flow rates specified and J 45096 does not have the capability to test the transmission oil cooling system at the maximum oil flow rate specification. Q: Why doesn't GM publish a specification for auxiliary transmission oil coolers? A: The auxiliary oil cooler used with GM vehicles does not contain an internal turbulator plate like the radiator tank oil cooler does. Therefore, there is no internal restriction that would affect the flow rate through the oil cooling system so a specification for auxiliary oil cooler is not required. Keep in mind, kinks and damage to the auxiliary cooler and lines can affect the flow rate through the system. Q: Why did GM drop the labor time for transmission repairs? A: The labor for flushing and flow testing the transmission oil cooling system is included with the R&R; labor of the "K" labor operations that require transmission removal. The time required to use the J 45096 to perform the flush and flow test is much less than that of the J 35944-A. The warranty labor savings allowed GM to provide the J 45096 at no cost to dealerships. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 4535 Q: Why didn't the machine come with the adapters to hook up to the car? A: The J 45096 was designed to use the previously released essential cooler line adapters for the J 35944-A. All adapters are listed on page 17 of the Operation Manual and can be ordered from Kent-Moore at 1-800-345-2233. Q: How do I connect the J 45096 to a Catera, Prizm or a Vibe? A: These vehicles, along with many other models, only require barbed fittings to connect to the rubber cooler hose. These fittings are commercially available and already found in many shops. Q: Why didn't I receive an Operation Manual with the machine? A: The Operation Manual was packaged in the upper portion of the shipping carton. If the shipping carton was lifted off the base without opening the top of the carton, the Operation Manual could have been discarded with the carton. Replacement Operation Manual packages can be obtained from Kent-Moore Customer Service at 1-800-345-2233. Q: Why can't I re-use the transmission fluid I use for flushing? A: The very fine metal and clutch material debris from the transmission failure in the ATF causes failures with the hall effect speed sensors that are used to measure the flow rate. To avoid costly repairs, expensive filters, regular maintenance and problems caused by a partially restricted filter, the filter was not included. Q: What do I do if I need service on my machine? A: Call Kent-Moore Customer Service at 1-800-345-2233. The J 45096 has a one-year warranty. Q: Can I flush and flow engine oil coolers? A: The engine oil cooler flow rates, the appropriate adapters and an acceptable procedure are currently under development. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4540 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4541 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4542 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4543 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Pressure Test Port, A/T > Component Information > Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Technical Service Bulletins > A/T Control - DTC P0756 Diagnostic Tips Valve Body: Technical Service Bulletins A/T Control - DTC P0756 Diagnostic Tips INFORMATION Bulletin No.: 01-07-30-036H Date: January 29, 2009 Subject: Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start Models: 2009 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70) Supercede: This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle). Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC: ^ This is a performance code. This means that a mechanical malfunction exists. ^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set. ^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips. ^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages. ^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking. It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Specifications > Electrical Specifications Valve Body: Electrical Specifications Component Resistance Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Specifications > Electrical Specifications > Page 4556 Valve Body: Mechanical Specifications 4L60 Automatic Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. FWD Accumulator Cover To Valve Body ............................................................................................ ............................................................................... 8 Valve Body To Case ......................................... .............................................................................................................................................................. ..... 8 Pressure Control Solenoid To Valve Body ................................................................................. ......................................................................................... 8 Detent Spring To Valve Body ................. .............................................................................................................................................................. ............. 18 Auxiliary Valve Body To Case .......................................................................................... .................................................................................................. 8 4L60-E Automatic Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. FWD Accumulator Cover To Valve Body ............................................................................................ ............................................................................... 8 Valve Body To Case ......................................... .............................................................................................................................................................. ..... 8 Pressure Control Solenoid To Valve Body ................................................................................. ......................................................................................... 8 Detent Spring To Valve Body ................. .............................................................................................................................................................. ............. 18 Auxiliary Valve Body To Case .......................................................................................... .................................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations Valve Body: Locations Checkball Locations Case Checkballs and Filters Locations Control Valve Body Checkball Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations > Page 4559 Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations > Page 4560 Valve Body: Locations Shift Solenoids Electronic Component Location Views Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations > Page 4561 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service Valve Body: Service and Repair In-Vehicle Service Control Valve Assembly 1. Disconnect battery ground cable. 2. Disconnect TV cable at throttle lever, then raise and support vehicle. 3. Drain transmission fluid, then remove transmission oil pan, filter and gasket. Fig.12 Auxiliary Valve Body Replacement 4. Remove two bolts that attach auxiliary accumulator valve tube to control valve assembly and accumulator valve body assembly, Fig. 12. 5. Remove two tube clamps, gently pry tube loose from oil pump assembly, then the auxiliary accumulator valve body assembly. 6. Disconnect electrical connectors at valve body. 7. Remove detent spring and roller assembly from valve body and remove valve body to case bolts. 8. Remove valve body assembly while disconnecting manual control valve link from range selector inner lever and removing throttle lever bracket from TV link. 9. Reverse procedure to install. Auxiliary Valve Body 1. Raise and support vehicle, then drain transmission fluid. 2. Remove transmission oil pan and filter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4564 Fig.12 Auxiliary Valve Body Replacement 3. Remove two bolts that attach auxiliary accumulator valve tube to control valve assembly and accumulator valve body assembly, Fig. 12. 4. Remove two tube clamps, gently pry tube loose from oil pump assembly and auxiliary accumulator valve body assembly. 5. Remove three auxiliary accumulator valve body to transmission case attaching bolts. 6. Remove auxiliary valve body and check ball. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4565 Valve Body: Service and Repair Unit Repair Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN ^ Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). ^ Filter seal may be stuck in the pump. INSPECT ^ Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4566 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4567 Manual Valve Link Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4568 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with 0-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4569 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). ^ Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4570 Case Checkballs And Filters TOOL REQUIRED: ^ J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. ^ The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. ^ Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). ^ Gasket (47) identified by a "C". Gasket (52) identified by a "V". ^ Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT ^ Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4571 Case Checkballs And Filters Filter Screen - Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4572 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4573 Control Valve Assembly - Legend Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4574 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4575 Manual Valve Link Outside Electrical Connector CLEAN ^ Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT ^ Some valves are under pressure - cover the bores while removing roll pins and retainer clips. ^ Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4576 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN ^ All valves, springs, bushings and control valve body in clean solvent. ^ Dry using compressed air. INSPECT ^ All valves and bushings for: Porosity - Scoring - Nicks - Scratches ^ Springs for damaged or distorted coils. ^ Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE ^ Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). ^ Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). ^ Connect the manual valve link (89) to the inside detent lever (88). ^ Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT ^ Wiring harness connections to electrical components. ^ To correctly hook up the wires, see the wiring diagrams. ^ The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN ^ Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). ^ The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4577 TIGHTEN ^ Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN ^ Torque to 12 Nm (9 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4578 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT ^ Seal (29) is reusable. 4. Filter assembly (31). INSPECT ^ Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4579 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4580 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. ^ Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five 0-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4581 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT ^ Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4582 ^ Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN ^ All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. ^ Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. 2. Pistons for: ^ Seal damage. 3. Springs for: ^ Damaged or distorted coils. 4. Valve body casting and accumulator housing for: ^ Porosity. ^ Cracks. ^ Interconnected passages. ^ Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4583 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4584 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4585 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4586 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4587 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN ^ Control valve assembly and accumulator housing (51) thoroughly in clean solvent. ^ Air dry. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4588 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4589 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4590 CLEAN ^ All components. INSPECT ^ All valves, pistons, springs and seals for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4591 ASSEMBLE ^ Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE ^ Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4592 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: ^ Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4593 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN ^ Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4594 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4595 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. ^ # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4596 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT ^ Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN ^ Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4597 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. ^ Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 4598 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN ^ Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Fluid > Component Information > Specifications > Capacity Specifications Clutch Fluid: Capacity Specifications Fill the clutch master cylinder to the "Full" or "MAX" mark on the reservoir. Do not overfill. Caution: Should accidental spillage occur, rinse the area thoroughly with water. Pay special attention to any electrical wires, parts, harnesses, rubber or painted surfaces. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Fluid > Component Information > Specifications > Capacity Specifications > Page 4605 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Pilot Bearing > Component Information > Technical Service Bulletins > M/T - Clutch Pilot Bushing and Bearings Pilot Bearing: Technical Service Bulletins M/T - Clutch Pilot Bushing and Bearings File In Section: 7 - Transmission Bulletin No.: 46-73-02 Date: October, 1994 INFORMATION Subject: Clutch Pilot Bushings and Bearings Models: 1988-95 Chevrolet and GMC Truck Light Duty Trucks with 4.3L, 5.0L, 5.7L, 6.2L, 6.5L, 7.4L Engines and Manual Transmission A worn or damaged clutch pilot bushing or bearing, located in the end of the crankshaft, can be the cause of various clutch and transmission concerns including: ^ Noise when the clutch pedal is depressed ^ Transmission noise ^ Clutch shudder on launch ^ Difficult shifting or excessive clash into reverse A worn clutch pilot bushing will not properly support the transmission input shaft. Without sufficient support, the front of the input shaft can move out of location resulting in transmission noise or clutch shudder on engagement. A damaged clutch pilot bushing or bearing may continue to turn the transmission input shaft when the clutch is released. This rotation can then cause difficult shifting or gear clash. Anytime a transmission or clutch is removed for repair, a new clutch pilot roller bearing should be installed. The end of the transmission input shaft that contacts the pilot roller bearing should also be inspected for damage. When installing the pilot roller bearing, the chamfer or lead-in to the I.D. should be installed facing the rear of the vehicle. This chamfer will help guide the input shaft into the roller bearing. This bearing is pre-lubed with a high temperature grease and does not require additional lubrication. The bearing listed below will fit all 1988-95 4.3L, 5.OL, 5.7L, 6.2L, 6.5L, and 7.4L light duty engines. Do not use a bronze clutch pilot bushing. Parts Information P/N Description Qty 14061685 Bearing, clutch Pilot 1 Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON Continuously Variable Transmission/Transaxle: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON > Page 4618 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Vehicle - Engine Crankcase and Subsystems Flushing Info. INFORMATION Bulletin No.: 04-06-01-029E Date: April 29, 2010 Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance Customer Service Experience Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System). An Overview of Proper Vehicle Service General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and accelerate the process of fluid changing with these flushing machines. Engine Crankcase Flushing General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty. GM Authorized Service Information: Detailed, Descriptive, and Complete If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required, provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on some engines, though under normal circumstances, this service is not part of the maintenance requirements. GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject. Subsystem Flushing Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice is NOT required or recommended for normal service operations. The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement. Approved Transmission Flushing Tool (Transmission Cooler Only) The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and Flow Test in SI using the J 45096. Service Is Important to You and Your Customer General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. > Page 4624 Providing responsible services at the proper intervals will greatly aid your dealership with repeat business, and additional services when required. Most customers appreciate and gain trust in the dealership that informs and offers them just what they need for continued trouble-free operation. Examine your service department's practices and verify that all Service Consultants and Technicians focus on customer satisfaction, vehicle inspections, and other products at time of service. Use this opportunity to upgrade the services you provide to your customers. Here are a few suggestions: - Take the time required to align your dealership service practices with the new GM Simplified Maintenance Schedule. Use the new vehicle Owner's Manual Maintenance I and II schedules to create a "mirror image" in your advertising and dealer service pricing that is easily understandable to your customer. Taking advantage of this new service strategy may greatly increase your dealership service sales and customer retention while decreasing the frequency of visits and inconvenience to your customer. - Review your program to ensure that all vehicles coming in are evaluated for safety and wear items. Examine all vehicles for tire condition, signs of misalignment, brake wear, exterior lamp functionality, exhaust condition, A/C cooling performance, SRS or Air Bag MIL, along with Service Engine Soon or Check Engine indicators. If the Service Engine Soon or Check Engine MIL is illuminated, it is vital that you inform the customer of the concerns with ignoring the indicator and what the required repair would cost. In addition to the possibility of increased emissions and driveability concerns, many customers are unaware that lower gas mileage may also result, with additional cost to the customer. - Be complete in your service recommendations. Some sales opportunities are not being fully pursued nationally. Focus on overlooked but required maintenance that has real benefits to the customer. Many vehicles are equipped with cabin air filters. If these filters are used beyond replacement time, they may impede airflow decreasing A/C and heating performance. Make sure these filters are part of your recommended service. Note that some of our vehicles may not have been factory equipped but will accept the filters as an accessory. - Express the value in maintaining the finish quality of the customer's vehicle at the Maintenance I and II visits. More fully utilize the vehicle prep personnel you already have in place. In today's world, many people simply ignore the finish of their vehicle, at best infrequently using an automatic car wash for exterior cleaning. Offer vehicle detailing services in stages from just a wash and wax to a complete interior cleaning. When paired with the Simplified Maintenance visit, this will increase customer satisfaction. On return, the customer gets a visibly improved vehicle that will be a source of pride of ownership along with a vehicle that is now fully maintained. Also, reinforce the improved resale value of a completely maintained vehicle. - For customers who clean and maintain the appearance of their vehicles themselves encourage the use of GM Vehicle Care products. Many customers may have never used GM Car Wash/Wax Concentrate, GM Cleaner Wax or a longtime product, GM Glass Cleaner, which is a favorite of many customers who try it just once. If your dealership give samples of these products with new car purchases, customers may already be sold on the product but not willing to make a special trip to the dealership. Capitalize on sales at this time. Stock shelves right at the Service counter with these products and consider instituting compensation programs for Service Consultants who suggest these products. Many consumers faced with an intimidating wall full of car care products sold at local auto parts stores may find it comforting to purchase a fully tested product sold by GM that they know will not harm the finish of their vehicle. We suggest these competitively priced basic vehicle care products to emphasize: In USA: - #12378401 GM Vehicle Care Wash/Wax Concentrate 16 fl. oz. (0.473L) - #89021822 GM Vehicle Care Glass Cleaner Aerosol 18 oz. (510 g) - #12377966 GM Vehicle Care Cleaner Wax 16 fl. oz. (0.473L) - #1052929 GM Vehicle Care Chrome and Wire Wheel Cleaner 16 fl. oz. (0.473L) - #88861431 GM Vehicle Care Odor Eliminator 24 fl. oz. (0.710L) In Canada: - #10953203 GM Vehicle Care Wash & Wax Concentrate 473 mL - #992727 GM Glass Cleaner Aerosol 500 g - #10952905 GM Vehicle Care Liquid Cleaner/Wax 473 mL - #10953013 GM Vehicle Care Chrome Cleaner and Polish 454 mL - #10953202 GM Vehicle Care Wheel Brite 473 mL - #88901678 GM Vehicle Care Odor Eliminator 473 mL - Display signboards with the installed price for popular GM Accessories such as running boards and Tonneau Covers. Customers may not think to ask about these desirable items at the time of a service visit. - Finally, take advantage of the GM Goodwrench initiatives (Tire Program, Goodwrench Credit Card, etc. / Dealer Marketing Association (DMA) Promotions in Canada) to provide the customer with more reasons to identify your dealership as the best place to go for parts and service. Remember to utilize ALL of the service aspects you possess in your dealership to satisfy and provide value to your customer. Many businesses exist profitably as an oil change location, a vehicle repair facility, or a detailing shop alone. You already have the capabilities of all three and provide these services with the inherent trust of your customer, under the GM Mark of Excellence. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Engine, A/T Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4629 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Other Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Vehicle - Engine Crankcase and Subsystems Flushing Info. INFORMATION Bulletin No.: 04-06-01-029E Date: April 29, 2010 Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance Customer Service Experience Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System). An Overview of Proper Vehicle Service General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and accelerate the process of fluid changing with these flushing machines. Engine Crankcase Flushing General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty. GM Authorized Service Information: Detailed, Descriptive, and Complete If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required, provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on some engines, though under normal circumstances, this service is not part of the maintenance requirements. GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject. Subsystem Flushing Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice is NOT required or recommended for normal service operations. The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement. Approved Transmission Flushing Tool (Transmission Cooler Only) The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and Flow Test in SI using the J 45096. Service Is Important to You and Your Customer General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Other Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. > Page 4635 Providing responsible services at the proper intervals will greatly aid your dealership with repeat business, and additional services when required. Most customers appreciate and gain trust in the dealership that informs and offers them just what they need for continued trouble-free operation. Examine your service department's practices and verify that all Service Consultants and Technicians focus on customer satisfaction, vehicle inspections, and other products at time of service. Use this opportunity to upgrade the services you provide to your customers. Here are a few suggestions: - Take the time required to align your dealership service practices with the new GM Simplified Maintenance Schedule. Use the new vehicle Owner's Manual Maintenance I and II schedules to create a "mirror image" in your advertising and dealer service pricing that is easily understandable to your customer. Taking advantage of this new service strategy may greatly increase your dealership service sales and customer retention while decreasing the frequency of visits and inconvenience to your customer. - Review your program to ensure that all vehicles coming in are evaluated for safety and wear items. Examine all vehicles for tire condition, signs of misalignment, brake wear, exterior lamp functionality, exhaust condition, A/C cooling performance, SRS or Air Bag MIL, along with Service Engine Soon or Check Engine indicators. If the Service Engine Soon or Check Engine MIL is illuminated, it is vital that you inform the customer of the concerns with ignoring the indicator and what the required repair would cost. In addition to the possibility of increased emissions and driveability concerns, many customers are unaware that lower gas mileage may also result, with additional cost to the customer. - Be complete in your service recommendations. Some sales opportunities are not being fully pursued nationally. Focus on overlooked but required maintenance that has real benefits to the customer. Many vehicles are equipped with cabin air filters. If these filters are used beyond replacement time, they may impede airflow decreasing A/C and heating performance. Make sure these filters are part of your recommended service. Note that some of our vehicles may not have been factory equipped but will accept the filters as an accessory. - Express the value in maintaining the finish quality of the customer's vehicle at the Maintenance I and II visits. More fully utilize the vehicle prep personnel you already have in place. In today's world, many people simply ignore the finish of their vehicle, at best infrequently using an automatic car wash for exterior cleaning. Offer vehicle detailing services in stages from just a wash and wax to a complete interior cleaning. When paired with the Simplified Maintenance visit, this will increase customer satisfaction. On return, the customer gets a visibly improved vehicle that will be a source of pride of ownership along with a vehicle that is now fully maintained. Also, reinforce the improved resale value of a completely maintained vehicle. - For customers who clean and maintain the appearance of their vehicles themselves encourage the use of GM Vehicle Care products. Many customers may have never used GM Car Wash/Wax Concentrate, GM Cleaner Wax or a longtime product, GM Glass Cleaner, which is a favorite of many customers who try it just once. If your dealership give samples of these products with new car purchases, customers may already be sold on the product but not willing to make a special trip to the dealership. Capitalize on sales at this time. Stock shelves right at the Service counter with these products and consider instituting compensation programs for Service Consultants who suggest these products. Many consumers faced with an intimidating wall full of car care products sold at local auto parts stores may find it comforting to purchase a fully tested product sold by GM that they know will not harm the finish of their vehicle. We suggest these competitively priced basic vehicle care products to emphasize: In USA: - #12378401 GM Vehicle Care Wash/Wax Concentrate 16 fl. oz. (0.473L) - #89021822 GM Vehicle Care Glass Cleaner Aerosol 18 oz. (510 g) - #12377966 GM Vehicle Care Cleaner Wax 16 fl. oz. (0.473L) - #1052929 GM Vehicle Care Chrome and Wire Wheel Cleaner 16 fl. oz. (0.473L) - #88861431 GM Vehicle Care Odor Eliminator 24 fl. oz. (0.710L) In Canada: - #10953203 GM Vehicle Care Wash & Wax Concentrate 473 mL - #992727 GM Glass Cleaner Aerosol 500 g - #10952905 GM Vehicle Care Liquid Cleaner/Wax 473 mL - #10953013 GM Vehicle Care Chrome Cleaner and Polish 454 mL - #10953202 GM Vehicle Care Wheel Brite 473 mL - #88901678 GM Vehicle Care Odor Eliminator 473 mL - Display signboards with the installed price for popular GM Accessories such as running boards and Tonneau Covers. Customers may not think to ask about these desirable items at the time of a service visit. - Finally, take advantage of the GM Goodwrench initiatives (Tire Program, Goodwrench Credit Card, etc. / Dealer Marketing Association (DMA) Promotions in Canada) to provide the customer with more reasons to identify your dealership as the best place to go for parts and service. Remember to utilize ALL of the service aspects you possess in your dealership to satisfy and provide value to your customer. Many businesses exist profitably as an oil change location, a vehicle repair facility, or a detailing shop alone. You already have the capabilities of all three and provide these services with the inherent trust of your customer, under the GM Mark of Excellence. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion Carrier Bearings: Adjustments 2 - Pinion Fig. 3 Installing shims To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed. 1. Ensure side bearing surfaces are clean and free of burrs. 2. Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used. 3. Install differential case in carrier, with bearing outer races in position. 4. Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment. 5. Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers. 6. Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing. 7. At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary. 8. Check case for zero endplay using a suitable dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6. 9. Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs. Fig. 4 Gear tooth contact pattern check 10. If pinion was not removed, check backlash and tooth pattern as follows: a. Apply suitable marking compound on ring gear teeth. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion > Page 4642 b. Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required. c. After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them. d. Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload. e. Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16---29 inch lbs. if new bearings are installed or 10---16 inch lbs. if original bearings are installed. f. If total rotational torque is not as specified, repeat steps 4 through 10. 11. If drive pinion was removed, remove differential case and shims, then proceed to ``Drive Pinion & Bearing Shim Adjustment'' procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion > Page 4643 Carrier Bearings: Adjustments 4 - Pinion Fig. 3 Installing shims To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed. 1. Ensure side bearing surfaces are clean and free of burrs. 2. Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used. 3. Install differential case in carrier, with bearing outer races in position. 4. Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment. 5. Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers. 6. Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing. 7. At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary. 8. Check case for zero endplay using a dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6. 9. Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs. Fig. 4 Gear tooth contact pattern check 10. If pinion was not removed, check backlash and tooth pattern as follows: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion > Page 4644 a. Apply marking compound on ring gear teeth. b. Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required. c. After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them. d. Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload. e. Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16-29 inch lbs. if new bearings are installed or 10-16 inch lbs. if original bearings are installed. f. If total rotational torque is not as specified, repeat steps 4 through 10. 11. If drive pinion was removed, remove differential case and shims, then proceed to DRIVE PINION & BEARING SHIM ADJUSTMENT procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear Differential Clutch: Service and Repair 7 1/2 - 8 1/2 Inch Ring Gear Cam Gear Clutch Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove retaining ring from end of cam gear, Fig. 8. 2. Remove discs and cam plate from gear, keeping all components in order. 3. Clean and inspect components, and replace any that are damaged, distorted or excessively worn. If cam gear must be replaced, refer to CAM GEAR SHIM SELECTION for shim selection procedures prior to case reassembly. 4. Position gear on flat surface with hub end up, and assemble cam plate onto gear with cam form down to mate with cam form on gear. 5. Assemble two eared discs, one splined disc and one wave washer on cam gear, starting with eared disc as shown in Fig. 8. 6. Alternately assemble three eared discs and two splined discs on cam gear hub, starting with eared discs. 7. Install retaining ring, ensuring that retainer is fully seated. Side Gear (RH) Clutch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 4649 Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove disc pack and shim from side gear, keeping components in order. 2. Clean and inspect components, and replace any that are damaged, deformed or excessively worn. If side gear must be replaced, refer to SIDE GEAR SHIM SELECTION for shim selection prior to case assembly. If side gear hub is scored or worn, inspect bore in case and replace assembly if bore is damaged or worn. 3. Alternately assemble eared discs and splined discs on side gear hub, starting with eared disc as shown in Fig. 8. 4. Install original shim or replacement shim of same thickness if original side gear is being used. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 4650 Differential Clutch: Service and Repair 8 7/8 Inch Ring Gear Cam Gear Clutch If cam plate or clutch discs must be replaced, the cam gear subassembly must be serviced as follows: 1. Measure and record overall length of gear assembly (front face of gear to back side of thrust ring, including shim). This dimension will be needed to reassemble unit if thrust ring is replaced. Do not replace thrust ring unless necessary. If ring is excessively worn or scored, check bore in case for scoring. If bore is scored, replace entire differential. 2. With gear hub end up, compress disc pack and install jaws of split ring bearing remover between the thrust ring and the top eared disc. Bevel side of bearing remover should face up toward thrust ring. 3. Place cam gear assembly with bearing remover attached in an arbor press supporting the bearing remover on both sides. 4. Install a 1-1/2 inch to 1-3/4 inch diameter plug on gear hub. Press against plug with ram of press to remove thrust ring. Keep components in proper order. 5. Place gear on bench with hub end up. 6. Assemble cam plate with cam form down to mate with cam form on gear. Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 7. Assemble onto cam plate: 2 eared discs, 1 splined disc, and 1 wave spring alternately, Fig. 8. 8. Assemble onto gear hub: 2 splined discs and 3 eared discs alternately, Fig. 8. 9. Locate cam gear assembly in arbor press with hub end up. Place thrust ring on gear hub and press to shoulder making sure that ring is square with hub. Compress disc pack by pushing down on the discs to keep the splined discs from becoming wedged between the thrust ring and gear shoulder while pressing the subassembly together. Side Gear (RH) Clutch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 4651 Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove shim and disc pack from side gear, keeping components in order. 2. Inspect discs and guide clips and replace as needed. 3. Inspect side gear and shim. If either component is damaged or excessively worn, differential assembly must be replaced. If gear hub is scored or abnormally worn, inspect corresponding bore in case. If case bore is damaged or oversize, differential assembly must be replaced. 4. Assemble eared and splined discs onto side gear hub, starting with eared disc as shown in Fig. 8. If original disc pack is used, ensure that discs are installed in original position. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 4652 Differential Clutch: Service and Repair 9 1/2 Inch Ring Gear Cam Gear Clutch Fig. 6 Cam Gear Thrust Ring Removal. Eaton Locking Differential 1. Measure and record overall length of cam gear assembly from front face of gear to back side of thrust ring, including shim. 2. With gear hub facing up, compress disc pack and insert jaws of suitable split ring bearing puller between thrust ring and top eared disc with bevel side of puller facing thrust ring, Fig. 6. 3. Support bearing remover in press and press cam gear from thrust ring using 1-3/4 inch diameter spacer. Keep all component in order as cam gear is removed. 4. Remove disc pack and cam plate from gear, clean and inspect components, and replace any that are damaged or excessively worn. Do not replace thrust ring and/or cam gear unless necessary. If ring or gear is excessively worn or scored, inspect bore in case. If case bore is scored, entire assembly must be replaced. If cam gear or thrust ring are replaced, shim thickness must be selected to provide original assembly dimension and proper differential pinion backlash. 5. Position cam gear on flat surface with hub end up and install cam plate with cam form down to mate with form on gear. Fig. 5 Exploded View Of Eaton Locking Differential 6. Assemble two eared discs, one splined disc and wave spring onto cam plate as shown in Fig. 5. If components are reused, they must be installed in original position. 7. Alternately assemble three splined and four eared discs on cam gear hub, as shown in Fig. 5. 8. Mount cam gear assembly in press and position thrust ring over gear hub. 9. Compress disc pack to prevent splined disc from being trapped, then press thrust ring onto gear until seated against shoulder of gear. 10. Inspect assembly to ensure that discs are properly assembled and that first splined disc (large spline) is properly located on cam plate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 4653 Side Gear (RH) Clutch Fig. 5 Exploded View Of Eaton Locking Differential 1. Remove shim and disc pack from gear keeping components in order. 2. Inspect discs and guide clips and replace as needed. 3. Inspect side gear and shim. If either component is scored or excessively worn, inspect case and replace entire assembly if case is defective. If either side gear or shim must be replaced, shim thickness must be determined. Refer to Shim Selection. See: Differential Carrier/Service and Repair 4. Alternately assemble splined and eared discs on side gear hub as shown in Fig. 5. If components are reused, they must be installed in original position. 5. Install original shim or new shim of equal thickness. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Axle Housing > Component Information > Service and Repair Differential Axle Housing: Service and Repair Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and support at the frame. 2. Position a suitable jack under rear axle housing and raise slightly to support axle assembly. 3. Remove rear wheels and drums, then disconnect shock absorbers from anchor plates. 4. Scribe reference marks between driveshaft and the pinion flange for assembly reference, then disconnect driveshaft and position aside. 5. Remove brake lines from axle housing, then disconnect brake lines from backing plate. 6. If equipped with a stabilizer bar, remove it. 7. Remove U-bolts and anchor plates. 8. Remove vent hose from axle housing and move the axle clear of springs, then lower axle from vehicle. 9. Reverse procedure to install. Tighten shock absorber nuts, inner U-bolt nuts and outer U-bolt nuts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage Fluid - Differential: Technical Service Bulletins Drivetrain - Rear Axle Lubricant Compatibility & Usage File in Section: 04 - Driveline Axle Bulletin No.: 99-04-20-001 Date: June, 1999 INFORMATION Subject: Rear Axle Lubricant Compatibility and Usage Models: 1999 Cadillac Escalade 1988-99 Chevrolet and GMC C/K, G Van and P1-3 Series Models Built after the VIN Breakpoints (C/K) listed. This bulletin is being revised to add the 1999 Model Year, VIN Breakpoint information, and additional text Please discard Corporate Bulletin Number 86-42-04 (Section 4 - Driveline/Axle). This bulletin is being issued to inform dealers about the compatibility and usage of the new Fuel Efficient SAE 75W-90 Synthetic Axle Lubricant, GM P/N 12378261 (In Canada use P/N 10953455), with current axles, and with the non-synthetic axle lubricant, GM P/N 1052271 (In Canada use P/N 10950849), for the rear axles on the above light-duty trucks. Testing has shown that the new synthetic lubricant will chemically attack the Room Temperature Vulcanizing (RTV) sealant. Use only the non-synthetic lubricant, P/N 1052271, in axles using RTV sealant (See 9.5 and 10.5 information below). American Axle and Manufacturing (A.A.M.) has approved the use of the new Fuel Efficient SAE 75W-90 synthetic axle lubricant for rear axles with the following restrictions: ^ All 8.6 inch axles are compatible as originally built. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage > Page 4661 ^ 9.5 inch axles on vehicles built prior to mid-February 1998 are NOT compatible because RTV sealant is used on the cover pans. On vehicles built after mid-February 1998 and equipped with 9.5 inch rear axles, synthetic lubricant, P/N 12378261, can be used because the RTV was replaced with a gasket. Other mid-February changes to the 9.5 inch rear axles include a new cover pan and cover pan fasteners common to other axles. Important: The new cover pan is not retrofittable to the housing of 9.5 inch axles on vehicles built prior to mid-February 1998. A new retrofit kit is available that will enable the use of synthetic lubricant for vehicles built after mid-February, 1998. ^ All 10.5 inch axles prior to March 3, 1999 are compatible if the axle shaft hub seal (RTV) is replaced with P/N 327739 gasket when changing to synthetic lubricant. As a product improvement, this new lubricant has been released into 1999 current production C/K vehicles built after the above VIN breakpoints (Except HD3SOO models which use 75W-140 synthetic lubricant, P/N 12346140). It is recommended that synthetic lubricant be used when changing rear axle lubricant for the following reasons: ^ Potential fuel economy ^ Lower operating temperature under severe usage conditions Important: ^ You do not need to wash/rinse any non-synthetic lubricant from the axle cavity when changing over to a synthetic lubricant. However, you should remove debris from the magnet and the bottom of the axle cavity whenever the axle fluid is changed. ^ On light-duty trucks equipped with locking differentials, do NOT use a limited-slip additive. Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage > Page 4662 Fluid - Differential: Technical Service Bulletins Drivetrain - Recommended Axle Lubricant File In Section: 0 - General Information Bulletin No.: 76-02-02A Date: October, 1998 INFORMATION Subject: Recommended Axle Lubricant Models: 1999 and Prior Rear Wheel Drive Passenger Cars, Light and Medium Duty Trucks, and Four Wheel Drive Vehicles This bulletin is being revised to add the 1998 and 1999 Model Years and add Vehicle Line and Recommended Axle Lubricant Information. Please discard Corporate Bulletin Number 76-02-02 (Section 0 - General Information). The following tables provide the latest information on recommended axle lubricant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Rear Axle Lubricant Compatibility & Usage > Page 4663 Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Specifications > Capacity Specifications Fluid - Differential: Capacity Specifications Rear Axle Oil, Pts. ............................................................................................................................... ................................................................................ 4 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Specifications > Capacity Specifications > Page 4666 Fluid - Differential: Fluid Type Specifications Locking Differential (G80) This Article has been updated by TSB # 76-02-02A. SAE 80W-90 GL5 Gear Lubricant, GM P/N 1052271. Do not use limited slip additive. Non-Locking Differential Rear Axle with Non Limited Slip or Non Locking Differentials HD-3500 Trucks (Dana 11.0 axles) Recommended Lubricant - GM P/N 12346140, SAE 75W-140 Synthetic Gear Lubricant. 1999 GMT 800 Trucks Recommended Lubricant - GM P/N 12378261, SAE 75W-90 Synthetic Axle Lubricant. All other non limited-slip or non locking differentials including B and D cars, S/T, M/L, G, P, and C/K trucks except GMT 800 trucks, and as noted above. Recommended Lubricant - GM P/N 1052271 or an SAE 80W90 GL-5 Gear Lubricant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner Pinion Bearing: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner > Page 4671 Fig. 10 Pinion depth gauge tool installation. Corvette Adjustment 1. Install pinion bearing races in housing using a suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, Fig. 8, noting the following: a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9. 4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. Installation 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner > Page 4672 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench. 8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 4 - Pinion Fig. 5 Drive pinion & bearing shim adjustment 1. Install front pinion bearing cup in carrier using tool J-7817 or equivalent. 2. Install spacer (E) into carrier bore, Fig. 5. 3. Slide rear pinion bearing and cap (F) onto thru bolt (D) and rear bearing into axle housing. 4. Install thru bolt (D), rear bearing and cap (F) into axle housing. 5. Assemble front bearing cone (A) and spacer (B) onto thru bolt. 6. Rotate nut and shaft while increasing torque on nut until a rotational torque of 15-22 inch lbs. is obtained. Rotate thru bolt back and forth when tightening nut to properly seat bearing. 7. Install discs on thru bolt assembly as shown in Fig. 5. Position carrier so dial indicator contact rod is directly over gauging area of gauge plate J-35118-2. Discs must be fully seated in side bearing bores. 8. Install bearing caps over gauge shaft discs, then the cap attaching bolts. torque attaching bolts to 40 ft. lbs. 9. With dial indicator rod contacting gauging area of J-35118-2, rock gauge shaft back and forth until dial indicator measures the greatest deflection, then zero dial indicator. 10. Rotate gauge shaft until shaft does not contact gauge plate, then note measurement. 11. Select correct pinion shim as follows: a. If reusing production pinion, and pinion is marked with a ``+,'' correct shim will have a thickness equal to gauge reading minus amount specified on pinion. b. If reusing production pinion, and pinion is marked with a `` - ,'' correct shim will have a thickness equal to gauge reading plus amount specified on pinion. c. If using a production or service pinion which has no marking, correct shim will have a thickness equal to gauge reading. 12. Install selected pinion shim into carrier, then press rear pinion bearing cup into carrier using tool J-5590 or equivalent. 13. Press rear pinion bearing onto pinion using a bearing installation tool, then install pinion in carrier. 14. Install collapsible spacer and front bearing onto pinion while supporting pinion under head. 15. Install oil seal, companion flange and new nut on pinion, then tighten pinion nut until a rotating torque of 10-25 inch lbs. with new bearings or 5-12 inch lbs. with original bearings is obtained while rotating pinion forwards to seat bearings. 16. If preload is excessive after tightening pinion nut, replace collapsible spacer and repeat steps 14 and 15. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner > Page 4673 Pinion Bearing: Adjustments Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner > Page 4674 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner > Page 4675 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear Fig. 9 Pinion depth gauge installation PINION DEPTH, ADJUST If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION, INSTALL 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Borg Warner > Page 4676 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. Using and inch lb. torque wrench, check pinion preload by rotating pinion with wrench. Preload should be at 20-25 inch lbs. or less on new bearings or 10-15 inch lbs. on used bearings. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion Pinion Bearing: Service and Repair Borg Warner - 2 Pinion 1. Scribe reference mark between drive pinion and driveshaft yoke, then hold yoke with suitable tool and remove pinion nut and yoke. If yoke shows wear in the seal-to-flange contacting surface, the yoke should be replaced. 2. Install original pinion nut a few turns on pinion shaft, then using hammer and drift, tap pinion shaft out of pinion housing. Hold gear end of pinion shaft when removing to prevent it from falling from axle housing. On Corvette models, the pinion preload shims may stick to the pinion housing or the rear bearing during removal. These shims must be collected and kept together for use during reassembly. 3. Remove and discard pinion nut and collapsible spacer. 4. If being replaced, remove front and rear bearing races from pinion housing using drift positioned in race slots and hammer. 5. If rear pinion bearing is being replaced, remove using arbor press and adapters. Measure and record thickness of shim which is found under rear bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 4679 Pinion Bearing: Service and Repair Corporate and Eaton PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 4680 b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner Pinion Gear: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner > Page 4685 Fig. 10 Pinion depth gauge tool installation. Corvette Adjustment 1. Install pinion bearing races in housing using a suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, Fig. 8, noting the following: a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9. 4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. Installation 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner > Page 4686 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench. 8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 4 - Pinion Fig. 5 Drive pinion & bearing shim adjustment 1. Install front pinion bearing cup in carrier using tool J-7817 or equivalent. 2. Install spacer (E) into carrier bore, Fig. 5. 3. Slide rear pinion bearing and cap (F) onto thru bolt (D) and rear bearing into axle housing. 4. Install thru bolt (D), rear bearing and cap (F) into axle housing. 5. Assemble front bearing cone (A) and spacer (B) onto thru bolt. 6. Rotate nut and shaft while increasing torque on nut until a rotational torque of 15-22 inch lbs. is obtained. Rotate thru bolt back and forth when tightening nut to properly seat bearing. 7. Install discs on thru bolt assembly as shown in Fig. 5. Position carrier so dial indicator contact rod is directly over gauging area of gauge plate J-35118-2. Discs must be fully seated in side bearing bores. 8. Install bearing caps over gauge shaft discs, then the cap attaching bolts. torque attaching bolts to 40 ft. lbs. 9. With dial indicator rod contacting gauging area of J-35118-2, rock gauge shaft back and forth until dial indicator measures the greatest deflection, then zero dial indicator. 10. Rotate gauge shaft until shaft does not contact gauge plate, then note measurement. 11. Select correct pinion shim as follows: a. If reusing production pinion, and pinion is marked with a ``+,'' correct shim will have a thickness equal to gauge reading minus amount specified on pinion. b. If reusing production pinion, and pinion is marked with a `` - ,'' correct shim will have a thickness equal to gauge reading plus amount specified on pinion. c. If using a production or service pinion which has no marking, correct shim will have a thickness equal to gauge reading. 12. Install selected pinion shim into carrier, then press rear pinion bearing cup into carrier using tool J-5590 or equivalent. 13. Press rear pinion bearing onto pinion using a bearing installation tool, then install pinion in carrier. 14. Install collapsible spacer and front bearing onto pinion while supporting pinion under head. 15. Install oil seal, companion flange and new nut on pinion, then tighten pinion nut until a rotating torque of 10-25 inch lbs. with new bearings or 5-12 inch lbs. with original bearings is obtained while rotating pinion forwards to seat bearings. 16. If preload is excessive after tightening pinion nut, replace collapsible spacer and repeat steps 14 and 15. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner > Page 4687 Pinion Gear: Adjustments Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner > Page 4688 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner > Page 4689 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear Fig. 9 Pinion depth gauge installation PINION DEPTH, ADJUST If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION, INSTALL 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Borg Warner > Page 4690 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. Using and inch lb. torque wrench, check pinion preload by rotating pinion with wrench. Preload should be at 20-25 inch lbs. or less on new bearings or 10-15 inch lbs. on used bearings. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion Pinion Gear: Service and Repair Borg Warner - 2 Pinion 1. Scribe reference mark between drive pinion and driveshaft yoke, then hold yoke with suitable tool and remove pinion nut and yoke. If yoke shows wear in the seal-to-flange contacting surface, the yoke should be replaced. 2. Install original pinion nut a few turns on pinion shaft, then using hammer and drift, tap pinion shaft out of pinion housing. Hold gear end of pinion shaft when removing to prevent it from falling from axle housing. On Corvette models, the pinion preload shims may stick to the pinion housing or the rear bearing during removal. These shims must be collected and kept together for use during reassembly. 3. Remove and discard pinion nut and collapsible spacer. 4. If being replaced, remove front and rear bearing races from pinion housing using drift positioned in race slots and hammer. 5. If rear pinion bearing is being replaced, remove using arbor press and adapters. Measure and record thickness of shim which is found under rear bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 4693 Pinion Gear: Service and Repair Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 4694 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 4695 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear PINION DEPTH ADJUSTMENT Fig. 9 Pinion Depth Gauge Installation If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly tool No. J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION INSTALLATION 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 4696 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Dana/Spicer Full Floating Axle Axle Bearing: Service and Repair Dana/Spicer Full Floating Axle 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Dana/Spicer Full Floating Axle > Page 4702 Axle Bearing: Service and Repair Saginaw Full Floating Axle Bearing & Cup Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Chevrolet Full Floating Axle Shaft Assembly: Description and Operation Chevrolet Full Floating Fig. 5 Full floating rear axle The straddle mounted drive pinion is supported at the front by two opposed tapered roller bearings. The pinion gear roller bearing consists of an outer race and roller assembly and a precision ground diameter on the pinion pilot functions as an inner race. On units with 10-1/2 inch ring gear, Fig. 5, side bearing preload and ring gear to pinion backlash are controlled by side bearing adjusting rings threaded into the carrier. Pinion depth is controlled by a shim located between the pinion bearing retainer assembly and axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Chevrolet Full Floating > Page 4707 Axle Shaft Assembly: Description and Operation Chevrolet Salisbury Semi-Floating Salisbury type semi-floating rear axle Semi-floating Rear Axle W/9 1/2 Inch Ring Gear In these axles, the axle housing and differential carrier are cast into an integral assembly. The drive pinion assembly is mounted in two opposed tapered roller bearings. The pinion bearings are preloaded by a spacer behind the front bearing. The pinion is positioned by a washer between the head of the pinion and the rear bearing. The differential is supported in the carrier by two tapered roller side bearings. These bearings are preloaded by spacers located between the bearings and carrier housing. The differential assembly is positioned for proper ring gear and pinion backlash by varying these spacers. The differential case houses two side gears in mesh with two pinions mounted on a pinion shaft which is held in place by a lock pin. The side gears and pinions are backed by Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Chevrolet Full Floating > Page 4708 thrust washers. Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jackstands under frame side rails. Support axle housing with a suitable jack. 2. Drain lubricant from axle housing and remove propeller shaft. 3. Remove wheel and brake drum. 4. Disconnect parking brake cable from lever and at brake flange plate. 5. Disconnect hydraulic brake lines from connector and lower shock mounting from axle brackets. 6. Remove vent hose from axle vent fitting if equipped. 7. Disconnect height-sensing and brake proportioning valve linkage if equipped. 8. Support assembly with a hydraulic jack and remove rear stabilizer bar. 9. Remove U-bolts, spring plates and spacers from axle assembly. 10. Lower jack and axle assembly. 11. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Chevrolet Full Floating > Page 4709 Axle Shaft Assembly: Description and Operation Dana/Spicer Full Floating Fig. 3 Axle, Hub & Drum Components. This axle, Fig. 3, is similar to Salisbury type units. However, the axle shafts are full floating and the drive pinion incorporates two shim packs. The inner shim pack controls pinion depth, while the outer pack controls pinion bearing preload. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Chevrolet Full Floating > Page 4710 Axle Shaft Assembly: Description and Operation GMC Single Speed GMC single speed rear axle of 11,000 lbs. rated capacity This axle, Fig. 8, is a full floating type and enables removal of the axle shafts without removing the truck load or raising the rear axle. The drive pinion is straddle mounted and supported at the rear end by a straight roller bearing and at the front end by a double row ball bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Chevrolet Full Floating > Page 4711 Axle Shaft Assembly: Description and Operation Rockwell Full Floating Rockwell axle w/12 inch ring gear This axle, Fig. 13, employs a heavy duty hypoid drive pinion and ring gear. The differential and gear assembly is mounted on tapered roller bearings. The straddle mounted pinion has two tapered roller bearings in front of the pinion teeth which take the forward and reverse thrust, while a third bearing behind the pinion teeth carries the radial load. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Description and Operation > Page 4712 Rear Drive Axle Troubleshooting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle Axle Shaft Assembly: Service and Repair Rockwell Full Floating Axle Axle Assembly ROCKWELL REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing ROCKWELL REAR AXLE HOUSING 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Axle Shaft ROCKWELL REAR AXLE SHAFT 1. Remove hub cap, then install slide hammer adapter into tapped hole in axle flange. 2. Attach slide hammer onto adapter, then remove axle shaft from housing. 3. Install axle shaft, ensuring flange and hub splines align. 4. Install new gasket, position flange to hub, then install attaching bolts and tighten to specifications. Bearing & Cup ROCKWELL REAR WHEEL BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4715 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum ROCKWELL REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4716 Axle Shaft Assembly: Service and Repair GMC Single Speed Axle Axle Shaft REAR DRIVE AXLE Removing axle shaft. GMC single speed axle 1. Remove hub cap retaining cap screws and hub cap. 2. Install a slide hammer adapter into tapped hole in axle flange. 3. Attach slide hammer onto adapter and remove axle shaft from housing, Fig. 9. 4. Reverse procedure to install. Lubricate small end of axle shaft and install into housing using a new gasket. Torque axle flange cap screws on 15 ft. lbs. Wheel Bearings REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of retainer from slot or flat of locknut, then remove locknut from housing tube, Fig. 6. 3. Disengage tang of retainer from slot or flat of adjusting nut, then remove retainer. 4. Using tool shown in Fig. 6, remove adjusting nut from housing tube. Remove thrust washer. 5. Pull hub and drum assembly off axle housing. Remove oil seal and discard. 6. Using a suitable steel bar and an arbor press, press inner bearing cup from hub. Removing bearing retainer ring 7. Using a suitable pliers, remove outer bearing retaining ring, Fig. 10. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4717 8. Using an old axle shaft or equivalent, drive on axle shaft spacer to remove outer bearing assembly from hub. 9. Position axle shaft spacer and outer bearing into hub, ensuring larger side of bearing faces outer end of hub. 10. Position outer bearing cup into hub with thin edge facing toward outer end of hub, then press cup into hub. 11. Install retaining ring, then press cup into contact with ring. 12. Drive inner bearing cup into hub, then install new oil seal. 13. Reverse Steps 1 through 5 to complete installation, then adjust wheel bearings. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4718 Axle Shaft Assembly: Service and Repair Dana/Spicer Full Floating Axle Axle Assembly REAR DRIVE AXLE 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Shaft Replace REAR DRIVE AXLE Fig. 3 Axle, Hub & Drum Components. 1. Using a soft faced mallet, tap axle shaft flange lightly to loosen shaft. 2. Remove axle shaft attaching bolts, Fig. 3, then grip axle shaft rib with pliers and twist to start shaft removal. 3. Remove axle shaft from axle tube. 4. Reverse procedure to install. Wheel Bearing REAR WHEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4719 Axle Shaft Assembly: Service and Repair Chevrolet Salisbury Type Semi-Floating Axle Shaft, Replace REAR AXLE SHAFT Fig. 3 Removing differential pinion shaft 1. Raise vehicle and remove wheel and brake drum. 2. Drain lube from carrier and remove cover. 3. Remove differential pinion shaft lock screw and remove differential pinion shaft, Fig. 3. 4. Pull flanged end of axle shaft toward center of vehicle and remove C-lock from button end of shaft. 5. Remove axle shaft from housing, being careful not to damage seal. 6. Reverse foregoing procedure to install the axle shaft. Axle Assembly REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing REAR AXLE HOUSING Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jackstands under frame side rails. Support axle housing with a suitable jack. 2. Drain lubricant from axle housing and remove propeller shaft. 3. Remove wheel and brake drum. 4. Disconnect parking brake cable from lever and at brake flange plate. 5. Disconnect hydraulic brake lines from connector and lower shock mounting from axle brackets. 6. Remove vent hose from axle vent fitting if equipped. 7. Disconnect height-sensing and brake proportioning valve linkage if equipped. 8. Support assembly with a hydraulic jack and remove rear stabilizer bar. 9. Remove U-bolts, spring plates and spacers from axle assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4720 10. Lower jack and axle assembly. 11. Reverse procedure to install. Axle Shaft, Oil Seal & Bearing REAR AXLE SHAFT, OIL SEAL AND BEARING Fig. 1 Position Case For Clearance Fig. 2 Axle Shaft & Housing Components. Chevrolet Semi-Floating Axle 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove brake drum. 4. Remove carrier cover and drain fluid from axle. Remove gasket. 5. Remove locking screw. 6. Remove pinion shaft as follows: a. On models less locking differential, remove pinion shaft from case. b. On models with locking differential, remove pinion shaft partially and rotate case until pinion shaft touches the housing, Fig. 1. c. Using a screwdriver, rotate lock until it aligns with thrust block. 7. Push axle shaft flange toward differential. Do not hammer the shaft to move. 8. Remove lock (13), Fig. 2, from button end of axle shaft. 9. Slide axle shaft out from housing. Do not damage seal. 10. Using axle shaft bearing remover tool No. J-23689 or equivalent, remove oil seal. 11. Remove bearing as follows: a. Using axle shaft bearing remover tool No. J-23689 or equivalent, (for 8 1/2 ring gear), or axle shaft bearing remover tool No. J-29712 or equivalent (for 9 1/2 ring gear), carefully pull bearing from axle. b. Insert appropriate tool into axle bore so it grasps behind the bearing. Tighten nut and washer against bearing face, then pull bearing out using slide hammer with adapter tool No. J-2619-01 or equivalent. 12. Reverse procedure to install. Wheel Bearing/Oil Seal REAR WHEEL BEARING AND OIL SEAL 1. Remove axle shaft as previously described. 2. Use a suitable puller to remove bearing and oil seal. 3. Lubricate wheel bearing and cavity between seal lips with wheel bearing lubricant before installation. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4721 Axle Shaft Assembly: Service and Repair Axle Assembly ROCKWELL REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing ROCKWELL REAR AXLE HOUSING 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Axle Shaft ROCKWELL REAR AXLE SHAFT 1. Remove hub cap, then install slide hammer adapter into tapped hole in axle flange. 2. Attach slide hammer onto adapter, then remove axle shaft from housing. 3. Install axle shaft, ensuring flange and hub splines align. 4. Install new gasket, position flange to hub, then install attaching bolts and tighten to specifications. Bearing & Cup ROCKWELL REAR WHEEL BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4722 Hub & Drum ROCKWELL REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Axle Shaft REAR DRIVE AXLE Removing axle shaft. GMC single speed axle 1. Remove hub cap retaining cap screws and hub cap. 2. Install a slide hammer adapter into tapped hole in axle flange. 3. Attach slide hammer onto adapter and remove axle shaft from housing, Fig. 9. 4. Reverse procedure to install. Lubricate small end of axle shaft and install into housing using a new gasket. Torque axle flange cap screws on 15 ft. lbs. Wheel Bearings REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4723 2. Disengage tang of retainer from slot or flat of locknut, then remove locknut from housing tube, Fig. 6. 3. Disengage tang of retainer from slot or flat of adjusting nut, then remove retainer. 4. Using tool shown in Fig. 6, remove adjusting nut from housing tube. Remove thrust washer. 5. Pull hub and drum assembly off axle housing. Remove oil seal and discard. 6. Using a suitable steel bar and an arbor press, press inner bearing cup from hub. Removing bearing retainer ring 7. Using a suitable pliers, remove outer bearing retaining ring, Fig. 10. 8. Using an old axle shaft or equivalent, drive on axle shaft spacer to remove outer bearing assembly from hub. 9. Position axle shaft spacer and outer bearing into hub, ensuring larger side of bearing faces outer end of hub. 10. Position outer bearing cup into hub with thin edge facing toward outer end of hub, then press cup into hub. 11. Install retaining ring, then press cup into contact with ring. 12. Drive inner bearing cup into hub, then install new oil seal. 13. Reverse Steps 1 through 5 to complete installation, then adjust wheel bearings. Axle Assembly REAR DRIVE AXLE 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Shaft Replace REAR DRIVE AXLE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4724 Fig. 3 Axle, Hub & Drum Components. 1. Using a soft faced mallet, tap axle shaft flange lightly to loosen shaft. 2. Remove axle shaft attaching bolts, Fig. 3, then grip axle shaft rib with pliers and twist to start shaft removal. 3. Remove axle shaft from axle tube. 4. Reverse procedure to install. Wheel Bearing REAR WHEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Axle Shaft, Replace REAR AXLE SHAFT Fig. 3 Removing differential pinion shaft 1. Raise vehicle and remove wheel and brake drum. 2. Drain lube from carrier and remove cover. 3. Remove differential pinion shaft lock screw and remove differential pinion shaft, Fig. 3. 4. Pull flanged end of axle shaft toward center of vehicle and remove C-lock from button end of shaft. 5. Remove axle shaft from housing, being careful not to damage seal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4725 6. Reverse foregoing procedure to install the axle shaft. Axle Assembly REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing REAR AXLE HOUSING Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jackstands under frame side rails. Support axle housing with a suitable jack. 2. Drain lubricant from axle housing and remove propeller shaft. 3. Remove wheel and brake drum. 4. Disconnect parking brake cable from lever and at brake flange plate. 5. Disconnect hydraulic brake lines from connector and lower shock mounting from axle brackets. 6. Remove vent hose from axle vent fitting if equipped. 7. Disconnect height-sensing and brake proportioning valve linkage if equipped. 8. Support assembly with a hydraulic jack and remove rear stabilizer bar. 9. Remove U-bolts, spring plates and spacers from axle assembly. 10. Lower jack and axle assembly. 11. Reverse procedure to install. Axle Shaft, Oil Seal & Bearing REAR AXLE SHAFT, OIL SEAL AND BEARING Fig. 1 Position Case For Clearance Fig. 2 Axle Shaft & Housing Components. Chevrolet Semi-Floating Axle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4726 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove brake drum. 4. Remove carrier cover and drain fluid from axle. Remove gasket. 5. Remove locking screw. 6. Remove pinion shaft as follows: a. On models less locking differential, remove pinion shaft from case. b. On models with locking differential, remove pinion shaft partially and rotate case until pinion shaft touches the housing, Fig. 1. c. Using a screwdriver, rotate lock until it aligns with thrust block. 7. Push axle shaft flange toward differential. Do not hammer the shaft to move. 8. Remove lock (13), Fig. 2, from button end of axle shaft. 9. Slide axle shaft out from housing. Do not damage seal. 10. Using axle shaft bearing remover tool No. J-23689 or equivalent, remove oil seal. 11. Remove bearing as follows: a. Using axle shaft bearing remover tool No. J-23689 or equivalent, (for 8 1/2 ring gear), or axle shaft bearing remover tool No. J-29712 or equivalent (for 9 1/2 ring gear), carefully pull bearing from axle. b. Insert appropriate tool into axle bore so it grasps behind the bearing. Tighten nut and washer against bearing face, then pull bearing out using slide hammer with adapter tool No. J-2619-01 or equivalent. 12. Reverse procedure to install. Wheel Bearing/Oil Seal REAR WHEEL BEARING AND OIL SEAL 1. Remove axle shaft as previously described. 2. Use a suitable puller to remove bearing and oil seal. 3. Lubricate wheel bearing and cavity between seal lips with wheel bearing lubricant before installation. 4. Reverse procedure to install. Axle Housing REAR AXLE HOUSING 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Axle Shaft REAR AXLE SHAFT 1. Remove bolts that attach axle shaft flange to wheel hub. 2. Tap on flange with a rawhide mallet to loosen axle shaft, then remove axle shaft by twisting shaft with locking pliers. 3. Thoroughly clean both axle shaft flange and end of wheel hub. Any lubricant on these surfaces tends to loosen axle shaft flange bolts. 4. Place a new gasket over axle shaft and position axle shaft in housing so that shaft splines enter differential side gear. Position gasket so that holes are in alignment and install flange-to-hub attaching bolts. Bearing & Cup REAR WHEEL BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4727 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Borg Warner REAR DRIVE AXLE Fig. 1 Removing Axle Shaft. Borg Warner Axle Fig. 2 Removing Axle Shaft Bearing Retainer Nuts. Borg Warner Axle 1. Raise and support rear of vehicle, then remove wheel and tire assembly. 2. Remove brake caliper, then remove brake rotor. 3. Remove four nuts attaching axle shaft bearing retainer to axle housing. 4. Using puller and adapter J-21579 and J-2619-01 or equivalent, pull axle shaft from housing, Fig. 1. 5. To replace axle shaft bearing, split inner retainer with a suitable chisel, then remove retainer from axle shaft, Fig. 2. Using Tool No. J-22912-01 or equivalent, press bearing and seal from axle shaft. 6. Reverse procedure to install. When replacing oil seals, it should be noted right hand seal is identified by black bands, while left hand seal is identified by gold bands. Prior to installation, seal lips should be lightly coated with a suitable grease. When pressing bearing and seal onto axle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Component Information > Service and Repair > Rockwell Full Floating Axle > Page 4728 shaft, use tool No. J-8853-01 or equivalent. Position chamfer on outer diameter of bearing retainer toward bearing. On models with limited slip, both axle shaft splines should be fully engaged before axle shaft is rotated to maintain spline alignment. Corporate REAR DRIVE AXLE Fig. 3 Pinion Shaft Lock Screw & Axle C-lock. GM Axle 1. Raise vehicle and support vehicle, then remove wheel and brake drum or rotor. 2. Drain lube from carrier and remove cover. 3. Remove differential pinion shaft lock screw and remove differential pinion shaft, Fig. 3. 4. Pull flange end of axle shaft toward center of vehicle and remove C-lock from button end of shaft, Fig. 3. 5. Remove axle shaft from housing, being careful not to damage seal. 6. Reverse procedure to install the axle shaft. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Seals and Gaskets, Drive Axles > System Information > Service and Repair Seals and Gaskets: Service and Repair Fig. 3 Axle Shaft Bearing Removal Fig. 4 Axle Shaft Bearing Installation Fig. 5 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a suitable pry bar. Use care to avoid damaging axle housing. 3. Remove axle bearing using slide hammer J-2619, adapter J-2619-4, or axle bearing puller J-22813-01. The tangs of the axle bearing puller should engage the bearing outer race, Fig. 3. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer J-23765 or equivalent until bearing is seated in housing, Fig. 4. 5. Apply suitable gear lubricant to seal lips, then position seal on axle shaft seal installer J-23771 or equivalent. Install in axle housing, tapping into place until seal is flush with housing, Fig. 5. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Adjustments Wheel Bearing: Adjustments Front Wheel Bearings 1. Raise and support front of vehicle. 2. While rotating wheel assembly in forward direction, tighten spindle nut to specifications to fully seat the bearings. 3. Back off spindle nut until just loose, then hand tighten spindle nut. 4. Loosen nut until hole in spindle aligns with a spindle nut slot, then install new cotter pin. 5. When properly adjusted, endplay should measure 0.001-0.005 inch. 6. Install rotor/hub cap, then lower vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front Wheel Bearing: Service and Repair Front Front Wheel Rotor/Hub Assembly 2WD Figure 5 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 4737 Figure 6 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 4738 Wheel Bearing: Service and Repair Rear Dana/Spicer Full Floating Axle REAR WHEEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Bearing & Cup REAR HUB AND/OR BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum REAR HUB AND/OR BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 4739 5. Pull hub and drum straight off axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Hub > Component Information > Service and Repair Wheel Hub: Service and Repair Front Wheel Rotor/Hub Assembly 2WD Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Hub > Component Information > Service and Repair > Page 4743 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Drive/Propeller Shaft > Component Information > Technical Service Bulletins > Propeller Shaft Runout - Revised Specifications Drive/Propeller Shaft: Technical Service Bulletins Propeller Shaft Runout - Revised Specifications File In Section: 0 - General Information Bulletin No.: 86-01-24 Date: October, 1998 SERVICE MANUAL UPDATE Subject: Section 0/0C - Vibration Diagnosis - Revised Propeller Shaft Runout Specifications Models: 1993-98 Chevrolet and GMC M/L Models This bulletin revises the Propeller Shaft Runout Specifications for the following M/L Service Manuals: Model Year Section/Page Number 1998 0-57 1997 0C-11 1996 0C-10 1995 0C-10 1994 0C-11 1993 0C-11 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Drive/Propeller Shaft > Component Information > Technical Service Bulletins > Propeller Shaft Runout - Revised Specifications > Page 4749 Drive/Propeller Shaft: Technical Service Bulletins Propeller Shaft - Revised Runout Specification File In Section: 4 - Drive Axle Bulletin No.: 86-41-01 Date: September, 1998 SERVICE MANUAL UPDATE Subject: Section 4A - Propeller Shaft - Revised Propeller Shaft Runout Specifications Models: 1993-98 Chevrolet and GMC M/L Models This bulletin revises the Propeller Shaft Runout Specifications for the following M/L Service Manuals: Model Year Section/Page Number 1998 4-3 1997 4A-5 & 4A-13 1996 4A-13 1995 4A-13 1994 4A-1O 1993 4A-11 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Slip Yoke > Component Information > Technical Service Bulletins > Slip Yoke/U-Joint - Replacement and Servicing Slip Yoke: Technical Service Bulletins Slip Yoke/U-Joint - Replacement and Servicing File In Section: 4 - Drive Axle Bulletin No.: 46-41-01 Date: September, 1994 INFORMATION Subject: Slip Yoke Replacement and U-Joint Servicing Models: 1995 and Prior Light Duty Trucks U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed. Light duty trucks make use of three types of yokes: 1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole. 2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid. 3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication. The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Technical Service Bulletins > Slip Yoke/U-Joint - Replacement and Servicing Universal Joint: Technical Service Bulletins Slip Yoke/U-Joint - Replacement and Servicing File In Section: 4 - Drive Axle Bulletin No.: 46-41-01 Date: September, 1994 INFORMATION Subject: Slip Yoke Replacement and U-Joint Servicing Models: 1995 and Prior Light Duty Trucks U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed. Light duty trucks make use of three types of yokes: 1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole. 2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid. 3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication. The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Technical Service Bulletins > Page 4758 Universal Joint: Description and Operation The cross and roller type universal joint is a cross-shaped spider joint connecting two Y-shaped yokes. When design angles of more than 3-4° are exceeded, joints wear faster than normal. Original equipment joints are lubricated for life and cannot be lubricated on the vehicle. Never clamp propeller shaft tubing in a vice. Always clamp one of the yokes and support shaft horizontally. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes Universal Joint: Service and Repair Service Notes Before disassembling any universal joint, examine the assembly carefully and note the position of the grease fitting (if used). Also, be sure to mark the yokes in relation to the propeller shaft for assembly reference. Failure to observe these precautions may produce rough vehicle operation resulting in rapid wear and parts failure, as well as placing an unbalanced load on transmission, engine and rear axle. When universal joints are disassembled for lubrication or inspection, and the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes > Page 4761 Universal Joint: Service and Repair Cross & Roller Type Fig. 1 Production Type Universal Joints Which Use Nylon Injection Rings In Place Of Snap Rings Fig. 2 Service Type Universal Joints (Internal Snap Ring Type) Production universal joints cannot be reassembled because there are no bearing retainer grooves in the production bearing caps, Figs. 2 and 3. DISASSEMBLY 1. Mark shaft for assembly reference. 2. Support shaft in a horizontal line with universal joint bearing separator tool No. J 9522-3, equivalent or suitable vice. Fig. 4 External Snap Ring Universal Joint. 3. On models with external snap rings, remove snap rings, Fig. 4. If ring does not snap out of groove, relieve pressure on ring by tapping lightly on bearing cap. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes > Page 4762 4. On all models, place joint in tool No. J 9522-3 or equivalent with lower yoke ear supported by 1 1/8 inch socket, Fig. 5, then press out cap. If cap is not completely removed, insert spacer tool No. J 9522-5 or equivalent and continue to press, Fig. 6. If using a vice in place of special tool, use 1 1/8 inch socket to receive one cap and 5/8 inch socket to push opposite cap. 5. Rotate joint in tool or vice and press opposite cap out, then remove cross from yoke. 6. Inspect and clean retaining ring grooves. 7. Check cap bores for burrs and imperfections. ASSEMBLY 1. Use finger to coat needle bearings with thin layer of grease. Do not fill cups completely or use excessive amounts. Over lubrication may damage seals. 2. Put one bearing cap part way into one side of yoke, then insert cross into cap, Fig. 7. 3. Press cross and cap into yoke until cap is flush with yoke ear. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes > Page 4763 4. Press opposite cap into yoke, ensuring trunnion alignment, Fig. 8. 5. Continue to press cap into yoke ear while working cross to ensure free, unbinding movement until retainer groove clears inside of yoke. If binding occurs, stop pressing and check for misaligned bearings. 6. Snap retainers into place, Fig. 9. Yoke can be sprung slightly with firm hammer blow if retainer is difficult to seat, Fig. 10. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Fluid - M/T > Component Information > Specifications Fluid - M/T: Specifications TYPE: Astro/Safari .......................................................................................................................................... ...............................................................................AF S-Series 5-speed sectional case, RPO MY2 (NV3500) ....................................................................................................................................................GLS S-Series, others ................................................................................................................................... ................................................................................AF CAPACITY, Initial Fill: Astro, Safari: 4-speed 1987........................................................................................................................................ ...........................................2.3 Liters 4.9 Pints 5-speed 1987-90......................................................... .....................................................................................................................2.0 Liters 4.4 Pints S-Series: 4-speed Isuzu w/one piece bell housing trans. case 1987............................................................................................................... ........................................2.3 Liters 4.9 Pints 4-speed w/top load............................................................................................................................... ............................................2.0 Liters 4.2 Pints 5-speed top cover: 1987-91................................................................................................................................................ .........2.0 Liters 4.2 Pints 1992-94......................................................................................................... ................................................2.8 Liters 5.9 Pints 5-speed sectional cover........................................................................................................................ ............................................1.9 Liters 4.0 Pints Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations Shift Interlock Relay: Locations Behind LH side of I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations > Page 4773 Shift Interlock Relay: Diagrams C217A, Brake/Transmission Shift Interlock Relay C218A, Brake/Transmission Shift Interlock Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 4779 Brake Switch - TCC: Diagrams C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4783 Fluid Pressure Sensor/Switch: Locations The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4784 Fluid Pressure Sensor/Switch: Description and Operation Pressure Switch Manifold NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Pressure Switch Manifold (PSM) is a gear range sensing device used by the control module to sense what gear has been selected by the vehicle operator. The PSM is located on the valve body and consists of five pressure switches combined into one unit. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4789 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4790 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4791 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4792 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations Shift Interlock Solenoid: Locations Steering Column Wiring Steering Column Wiring Inside Steering Column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Interlock Solenoid > Component Information > Locations > Page 4802 C218A, BTSI Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4807 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4810 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN ^ Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). ^ Filter seal may be stuck in the pump. INSPECT ^ Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4813 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4814 Manual Valve Link Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4815 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with 0-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4816 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). ^ Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4817 Case Checkballs And Filters TOOL REQUIRED: ^ J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. ^ The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. ^ Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). ^ Gasket (47) identified by a "C". Gasket (52) identified by a "V". ^ Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT ^ Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4818 Case Checkballs And Filters Filter Screen - Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4819 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4820 Control Valve Assembly - Legend Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4821 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4822 Manual Valve Link Outside Electrical Connector CLEAN ^ Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT ^ Some valves are under pressure - cover the bores while removing roll pins and retainer clips. ^ Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4823 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN ^ All valves, springs, bushings and control valve body in clean solvent. ^ Dry using compressed air. INSPECT ^ All valves and bushings for: Porosity - Scoring - Nicks - Scratches ^ Springs for damaged or distorted coils. ^ Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE ^ Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). ^ Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). ^ Connect the manual valve link (89) to the inside detent lever (88). ^ Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN ^ Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT ^ Wiring harness connections to electrical components. ^ To correctly hook up the wires, see the wiring diagrams. ^ The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN ^ Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). ^ The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4824 TIGHTEN ^ Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN ^ Torque to 12 Nm (9 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4825 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT ^ Seal (29) is reusable. 4. Filter assembly (31). INSPECT ^ Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4826 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4827 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT ^ If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. ^ Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five 0-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4828 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT ^ Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4829 ^ Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN ^ All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. ^ Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. 2. Pistons for: ^ Seal damage. 3. Springs for: ^ Damaged or distorted coils. 4. Valve body casting and accumulator housing for: ^ Porosity. ^ Cracks. ^ Interconnected passages. ^ Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4830 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4831 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4832 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4833 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4834 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN ^ Control valve assembly and accumulator housing (51) thoroughly in clean solvent. ^ Air dry. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4835 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4836 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4837 CLEAN ^ All components. INSPECT ^ All valves, pistons, springs and seals for: ^ Porosity. ^ Scoring. ^ Nicks. ^ Scratches. Accumulator Housing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4838 ASSEMBLE ^ Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE ^ Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4839 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: ^ Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4840 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN ^ Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4841 Fig. 10 Control Valve Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4842 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. ^ # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4843 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT ^ Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN ^ Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4844 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. ^ Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4845 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN ^ Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Description and Operation Torque Converter Clutch Solenoid: Description and Operation OPERATION: The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two conditions must be met. 1. Internal transmission fluid pressure must be correct. 2. The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. This allows the converter clutch to apply, if the hydraulic pressure is correct. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations Shift Interlock Relay: Locations Behind LH side of I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - A/T > Shift Interlock Relay > Component Information > Locations > Page 4854 Shift Interlock Relay: Diagrams C217A, Brake/Transmission Shift Interlock Relay C218A, Brake/Transmission Shift Interlock Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 4860 Brake Switch - TCC: Diagrams C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4864 Fluid Pressure Sensor/Switch: Locations The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications > Page 4865 Fluid Pressure Sensor/Switch: Description and Operation Pressure Switch Manifold NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The Pressure Switch Manifold (PSM) is a gear range sensing device used by the control module to sense what gear has been selected by the vehicle operator. The PSM is located on the valve body and consists of five pressure switches combined into one unit. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View Transmission Position Switch/Sensor: Locations Location View Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4870 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Location View > Page 4871 Transmission Position Switch/Sensor: Locations Assembly View Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4872 Transmission Position Switch/Sensor: Diagrams C247, Park/neutral Position Switch C219A, Park/Neutral Position Switch C217, Park/Neutral Position Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Locations > Page 4873 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > ABS Main Relay > Component Information > Locations ABS Main Relay: Locations Fig. 223 EHCU/BPMV Replacement. The relay is located inside the Brake Pressure Modulator Valve (BPMV). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Brake Fluid Pump Relay > Component Information > Locations Brake Fluid Pump Relay: Locations Fig. 223 EHCU/BPMV Replacement. The relay is located inside the Brake Pressure Modulator Valve (BPMV). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Diagnostic Connector - ABS > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Locations Electronic Brake Control Module: Locations Four-Wheel Antilock Brake Wiring, Engine Compartment Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Locations > Page 4891 Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Locations > Page 4892 C181, 4WAL EHCU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Locations > Page 4893 Electronic Brake Control Module: Service and Repair Fig. 222 Intermediate Shaft & Universal Joint Assembly. Fig. 223 EHCU/BPMV Replacement. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove steering column intermediate shaft as follows: WARNING: Refer to Air Bags and Seat Belts / Air Bags (Supplemental Restraint Systems) / Service and Repair / Air Bag System Disarming & Arming. See: Body and Frame/Interior Moulding / Trim/Dash Board / Instrument Panel/Air Bag(s) Arming and Disarming a. Set wheels in straight ahead position. b. Mark upper universal joint yoke to steering shaft and lower yoke to steering gear wormshaft for installation reference. c. Remove upper and lower universal pinch bolts, Fig. 222. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Locations > Page 4894 d. Remove steering gear frame bolts, then lower the steering gear. e. Remove intermediate shaft and universal joint assembly. 2. Disconnect brake lines from bottom of combination valve. 3. Disconnect electrical connector from combination valve. 4. Remove master cylinder and combination valve assembly. 5. Remove brake lines from EHCU/BPMV module, then disconnect module electrical connectors. 6. Remove EHCU/BPMV bracket attaching nuts and bolt, Fig. 223. 7. Remove module and bracket assembly from vehicle, then the module from bracket assembly. 8. Reverse procedure to install, noting the following: a.a Torque module to bracket bolts to 5 ft. lbs. b. Torque bracket attaching bolt to 33 ft. lbs., then the two attaching nuts to 20 ft. lbs. c. Torque brake line fittings to module to 16 ft. lbs. d. Torque brake line fittings to combination valve to 15 ft. lbs. e. Install lower yoke onto steering gear wormshaft aligning marks made during removal. f. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. g. Raise steering gear into position while guiding upper yoke assembly onto steering shaft, align marks made during removal. h. Torque steering gear to frame bolts to 55 ft. lbs. i. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. j. Measure Cardan joint operating angle as shown in Fig. 222. Angle must be 34-39°. k. Bleed brake system and EHCU/BPMV module. See: Brake Bleeding Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Hydraulic Control Assembly - Antilock Brakes > Component Information > Service and Repair Hydraulic Control Assembly - Antilock Brakes: Service and Repair Fig. 222 Intermediate Shaft & Universal Joint Assembly. Fig. 223 EHCU/BPMV Replacement. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove steering column intermediate shaft as follows: WARNING: Refer to Air Bags and Seat Belts / Air Bags (Supplemental Restraint Systems) / Service and Repair / Air Bag System Disarming & Arming. See: Body and Frame/Interior Moulding / Trim/Dash Board / Instrument Panel/Air Bag(s) Arming and Disarming a. Set wheels in straight ahead position. b. Mark upper universal joint yoke to steering shaft and lower yoke to steering gear wormshaft for installation reference. c. Remove upper and lower universal pinch bolts, Fig. 222. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Hydraulic Control Assembly - Antilock Brakes > Component Information > Service and Repair > Page 4898 d. Remove steering gear frame bolts, then lower the steering gear. e. Remove intermediate shaft and universal joint assembly. 2. Disconnect brake lines from bottom of combination valve. 3. Disconnect electrical connector from combination valve. 4. Remove master cylinder and combination valve assembly. 5. Remove brake lines from EHCU/BPMV module, then disconnect module electrical connectors. 6. Remove EHCU/BPMV bracket attaching nuts and bolt, Fig. 223. 7. Remove module and bracket assembly from vehicle, then the module from bracket assembly. 8. Reverse procedure to install, noting the following: a.a Torque module to bracket bolts to 5 ft. lbs. b. Torque bracket attaching bolt to 33 ft. lbs., then the two attaching nuts to 20 ft. lbs. c. Torque brake line fittings to module to 16 ft. lbs. d. Torque brake line fittings to combination valve to 15 ft. lbs. e. Install lower yoke onto steering gear wormshaft aligning marks made during removal. f. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. g. Raise steering gear into position while guiding upper yoke assembly onto steering shaft, align marks made during removal. h. Torque steering gear to frame bolts to 55 ft. lbs. i. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. j. Measure Cardan joint operating angle as shown in Fig. 222. Angle must be 34-39°. k. Bleed brake system and EHCU/BPMV module. See: Brake Bleeding Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Locations > LH Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Locations > LH > Page 4903 Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Diagrams > RH Wheel Speed Sensor: Diagrams RH C189, RH Front Wheel Sensor C189, RH Front Wheel Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Diagrams > RH > Page 4906 Wheel Speed Sensor: Diagrams LH C190, LH Front Wheel Sensor C190, LH Front Wheel Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Service and Repair > Front Wheel Speed Sensor Wheel Speed Sensor: Service and Repair Front Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. Remove hub and rotor assembly. 4. Disconnect wheel sensor electrical connector. 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Service and Repair > Front Wheel Speed Sensor > Page 4909 Wheel Speed Sensor: Service and Repair Rear Wheel Speed Sensor Fig. 58 Rear Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Remove brake drum. 3. Remove primary brake shoe. 4. Disconnect sensor electrical connector. 5. Remove sensor wire from rear axle clip. 6. Remove speed sensor attaching bolts, Fig. 58, then remove sensor by pulling wire through hole in backing plate. 7. Reverse procedure to install. Torque speed sensor attaching bolts to 26 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding With ABS System Fig. 59 EHCU/BPMV Module Bleeding MANUAL BLEEDING The Electro-Hydraulic Control Unit Brake Pressure Modulator Valve Module (EHCU/BPMV) should be bled after replacement or if air is trapped in the unit or system. If system bleeding is required, the module must be bled thoroughly before the wheel cylinders and calipers. There are two bleeders on top of the unit that appear to be normal bleeders (figure 221). These are modulator bleeders and must remain closed when the unit is not pressurized. The internal bleeders are on either side of EHCU/BPMV module. The valves are used to open the internal passages within the EHCU/BPMV module. Both bleed valves must be rotated 1/4 to 1/2 turn counterclockwise before beginning the bleed process. The valve on the lefthand side is used for the rear brakes and the valve on the righthand side is used for the front brakes. NOTE: The ignition switch must be in the Off position or false diagnostic trouble codes may be stored. SPECIAL TOOL REQUIRED (or equivalent) ^ J-39177, Combination valve pressure bleeding tool (three required). PROCEDURE 1. Install combination valve depressor tool J-39177 to LH high pressure accumulator bleed stem of EHCU/BPMV module. 2. Install combination valve depressor tool J-39177 to RH high pressure accumulator bleed stem of EHCU/BPMV module. 3. Install combination valve depressor tool J-39177 to rear combination valve. 4. Ensure master cylinder fluid level, fill if required. 5. Bleed EHCU/BPMV module as follows: a. Slowly depress brake pedal one time and hold. b. Open left modulator bleeder, until fluid flows clearly or pedal is depressed, the close left bleeder. c. Slowly release brake pedal. d. Wait 15 seconds, then repeat steps until all air is bled from EHCU/BPMV module. e. Close LH internal bleed valve. Torque bleed valve to 7 Nm (5 ft lbs). f. Repeat preceding bleed steps for righthand bleed procedure. g. Remove special tools. 6. Ensure master cylinder fluid level, fill if required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 4914 7. Bleed wheel cylinder and calipers. 8. Turn ignition key to On position, then perform 3 function test with TECH 1 scanner. 9. Check brake pedal feel and braking performance; repeat procedure if required. General Information The braking system can be bled manually or with pressure bleeding equipment. If bleeding manually, check fluid level frequently. Brake fluid should never be reused. Before driving the vehicle, check brake operation to ensure a firm pedal has been obtained. Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always seal and wipe off brake fluid containers to prevent spills. Manual Fig. 7 Caliper Bleeding Hose Installation 1. If vehicle is equipped with a vacuum or hydraulic booster, relieve system by applying brakes several times with engine off. 2. Fill master cylinder reservoir with DOT 3 brake fluid. Maintain full level during bleeding procedures. 3. If master cylinder is replaced or suspected to have air in the bore, bleed it before calipers. a. Disconnect forward brake pipe connection at master cylinder and allow brake fluid to flow from connector port, then reconnect pipe but do not tighten. b. Slowly apply brake pedal to allow air to bleed from loose fitting, then tighten fitting before releasing brake pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air has been purged from bore. d. After all air has been removed from forward pipe, repeat procedure for rear pipe. 4. If the vehicle is equipped with four wheel anti-lock brakes (4WAL), the Brake Pressure Modular Valve (BPMV) may need to be bled. If the BPMV has been replaced or is suspected of having air trapped inside, bleed system as outlined in "Anti-Lock Brakes chapter." 5. Bleed each wheel in the following sequence: a. Right rear. b. Left rear. c. Right front. d. Left front. 6. Attach a suitable hose to wheel caliper valve and immerse opposite end of hose into a suitable clean container partially filled with clean brake fluid , Fig. 7. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 4915 7. Slowly apply brake pedal one time and hold, loosen the bleeder valve to purge air from caliper, then tighten bleeder valve and release pedal. 8. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from caliper. 9. Repeat bleeding sequence at each wheel until system is bled. 10. Check brake pedal for "sponginess and brake warning lamp for an indication of unbalanced pressure. Repeat bleeding procedure to correct either of these conditions. Pressure Fig. 8 Plastic Reservoir Bleeder Adapter Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 4916 Fig. 9 Cast Iron Reservoir Bleeder Adapter Installation A diaphragm type pressure bleeder must be used. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. Also, adapters are needed depending on the type of master cylinder reservoir used on the vehicle: Brake Bleeder Adapter (Plastic Reservoir) tool No. J 29567, or equivalent, Fig.8. Brake Bleeder Adapter (Cast Iron Reservoir) tool No. J 23518-01, or equivalent, Fig. 9. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 4917 Fig. 10 Combination Valve Bleeding Tool Installation 1. Fill the pressure tank at least 2/3 full of brake fluid. Bleeder must be bled each time fluid is added. 2. Charge pressure bleeder to 20-25 psi. 3. Use tool No. J 39177, or equivalent, to depress and hold valve stem on combination valve, Fig. 10. 4. Install master cylinder adapter tool required for type of reservoir, then install bleeder hose to adapter 5. Bleed each wheel in the following sequence: a. Right rear. b. Left rear. c. Right front. d. Left front. 6. Open bleeder tank valve. 7. Attach a hose to caliper bleeder valve and immerse the opposite end of the hose into a suitable, clean, container, partially filled with clean brake fluid. 8. Open bleeder valve at least 3/4 turn and allow fluid to flow until no air is seen in fluid, then close valve. 9. Repeat procedure at each wheel. 10. Check brakes for "sponginess. Repeat bleeding procedure if necessary. 11. Remove pressure bleeder, adaptors, and tools, then fill reservoir to proper level. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 4918 Brake Bleeding: Service and Repair Master Cylinder Bleeding This procedure can be performed with master cylinder on or off vehicle. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. It is not necessary to bleed entire hydraulic system after replacing master cylinder, providing master cylinder has been bled and filled during installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions Brake Warning Indicator: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4923 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4924 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4925 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4926 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4927 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4928 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4929 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4930 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4931 Brake Warning Indicator: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4932 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4933 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4934 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4935 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4936 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4937 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4938 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4939 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4940 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4941 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4942 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4943 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4944 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4945 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4946 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4947 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4948 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4949 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4950 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4951 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4952 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4953 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4954 Brake Warning Indicator: Electrical Diagrams Brake Warning System Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 4955 Brake Warning System Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Page 4956 Brake Warning Indicator: Description and Operation Battery voltage is supplied to the Brake Indicator through the GAGES Fuse and the PNK/BLK (39) wire when the Ignition Switch is in RUN or START. Ground is provided through the TAN/WHT (33) wire by the Park Brake Warning Switch, Brake Pressure Warning Lamp Switch or the Electronic Hydraulic Control Unit (EHCU) also called Antilock Electronic Brake Control Module. The Park Brake Warning Switch closes when the Parking Brake is applied. The Brake Indicator lights to alert the driver. The Brake Pressure Warning Lamp Switch closes to light the Brake Indicator when there is low brake fluid pressure in one of the two hydraulic brake systems. This could be caused by a leak in one of the brake lines. Refer to Switch reset procedure. This can only be accomplished after the system has been repaired. The Four-Wheel Antilock Brake Module grounds the Brake Indicator when the module senses certain malfunctions in the hydraulic portion of the system. The Four-Wheel Antilock Brake Module grounds the Antilock Indicator when the module senses a malfunction in the electrical or electronic portion of the system. Brake voltage input is supplied to the Module through the Stoplamp Switch whenever the brakes are applied. For the Four-Wheel Antilock Brake System Description and Diagnosis refer to Antilock Brake System See: Antilock Brakes / Traction Control Systems Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Brake Warning Indicator: Initial Inspection and Diagnostic Overview Preliminary Checks 1. Check condition of BRAKE fuse. If fuse is blown, locate and repair source of overload. replace fuse. 2. Refer to Brakes for the diagnostic circuit check and diagnostic trouble code identification. 3. Check to see that the BLK (2) fusible link is not burned out. replace if burned out. Circuit Operation Battery voltage is supplied to the Brake Indicator through the GAGES Fuse and the PNK/BLK (39) wire when the Ignition Switch is in RUN or START. Ground is provided through the TAN/WHT (33) wire by the Park Brake Warning Switch, Brake Pressure Warning Lamp Switch or the Electronic Hydraulic Control Unit (EHCU) also called Antilock Electronic Brake Control Module. The Park Brake Warning Switch closes when the Parking Brake is applied. The Brake Indicator lights to alert the driver. The Brake Pressure Warning Lamp Switch closes to light the Brake Indicator when there is low brake fluid pressure in one of the two hydraulic brake systems. This could be caused by a leak in one of the brake lines. Refer to Switch reset procedure. This can only be accomplished after the system has been repaired. The Four-Wheel Antilock Brake Module grounds the Brake Indicator when the module senses certain malfunctions in the hydraulic portion of the system. The Four-Wheel Antilock Brake Module grounds the Antilock Indicator when the module senses a malfunction in the electrical or electronic portion of the system. Brake voltage input is supplied to the Module through the Stoplamp Switch whenever the brakes are applied. For the Four-Wheel Antilock Brake System Description and Diagnosis refer to Antilock Brake System See: Antilock Brakes / Traction Control Systems Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 4959 Brake Warning Indicator: Symptom Related Diagnostic Procedures Brake Indicator Does Not Light During A Warning Condition Or During The Antilock System Check Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 4960 Brake Indicator Remains ON With Ignition Switch In Run And Park Brake Off (Part 1 Of 2) Brake Indicator Remains ON With Ignition Switch In Run And Park Brake OFF (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Caliper > Component Information > Specifications Brake Caliper: Specifications Bleeder Valve 115 in.lb Brake Hose To Caliper Bolt 32 ft.lb Caliper Mounting Bolt 38 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Caliper > Component Information > Specifications > Page 4965 Brake Caliper: Description and Operation Fig. 4 Exploded View Of Disc Brake Caliper Assembly. The caliper assembly slides on its mounting surfaces, Fig. 4. Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboard side of the disc. This action causes the caliper assembly to slide until the outboard pad comes into contact with the disc, which in turn creates a slowing or stopping action. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Caliper > Component Information > Specifications > Page 4966 Brake Caliper: Testing and Inspection Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than .002 inch. If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Caliper > Component Information > Service and Repair > Removal/Installation Brake Caliper: Service and Repair Removal/Installation REMOVAL Fig. 2 Compressing Piston & Pad With C-clamp 1. Siphon enough brake fluid out of the master cylinder to bring fluid level to 1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore. 2. Raise and support vehicle, remove front wheels. 3. Using a C-clamp, as illustrated in Fig. 2, push piston back into its bore. 4. Remove two mounting bolts and lift caliper away from disc. INSTALLATION 1. Position caliper over disc, lining up mounting holes in caliper with holes in mounting bracket. If brake hose was not disconnected during removal, be sure not to kink it during installation. 2. Start mounting bolts through sleeves in inboard caliper ears and the mounting bracket, making sure ends of bolts pass under ears on inboard shoe. Right and left calipers must not be interchanged. 3. Push mounting bolts through to engage holes in the outboard ears. Then thread mounting bolts into bracket. 4. Torque mounting bolts to specifications. 5. If brake hose was removed, reconnect it and bleed the calipers. 6. Replace front wheels, lower vehicle and add brake fluid to master cylinder to bring level to 1/4 inch from top. Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Caliper > Component Information > Service and Repair > Removal/Installation > Page 4969 Brake Caliper: Service and Repair Disassembly/Inspection/Assembly DISASSEMBLY Fig. 4 Removing Piston From Caliper 1. Disconnect hose from the caliper being careful not to lose copper washers. 2. Remove caliper as outlined above. 3. Drain brake fluid from caliper. 4. Pad caliper interior with clean shop towels and apply compressed air to remove piston, Fig. 4. Use just enough air pressure to ease piston out of bore. When applying compressed air do not place fingers in front of piston in an attempt to catch or protect it as this could result in serious injury. 5. Carefully pry dust boot out of bore. 6. Using a small piece of wood or plastic, remove piston seal from bore. Do not use a metal tool of any kind to remove seal as it may damage bore. 7. Remove bleeder valve. INSPECTION Clean all parts in denatured alcohol, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than .002 inch. If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. ASSEMBLY Fig. 5 Installing Boot To Piston Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Caliper > Component Information > Service and Repair > Removal/Installation > Page 4970 Fig. 6 Installing Boot To Caliper 1. Lubricate caliper piston bore and new piston seal with clean brake fluid. Position seal in bore groove. 2. Lubricate piston with clean brake fluid and assemble a new boot into the groove in the piston so the fold faces the open end of the piston, Fig. 5. 3. Using care not to unseat the seal, insert piston into bore and force the piston to the bottom of the bore. 4. Position dust boot in caliper counterbore and install, Fig. 6. Check the boot installation to be sure the retaining ring molded into the boot is not bent and that the boot is installed below the caliper face and evenly all around. If the boot is not fully installed, dirt and moisture may enter the bore and cause corrosion. 5. If available, use new copper washers discarding the old washers and install the brake hose to the caliper. 6. Install pads and caliper assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Pad > Component Information > Service and Repair Brake Pad: Service and Repair REMOVAL 1. Remove caliper assembly as outlined above. 2. Remove inboard pad with retainer spring. Dislodge outboard pad and position caliper on the front suspension so the brake hose will not support the weight of the caliper. 3. Remove two sleeves from inboard ears of the caliper. 4. Remove four rubber bushings from the grooves in each of the caliper ears. INSTALLATION Fig. 3 Fitting Pad To Caliper 1. Lubricate new sleeves, rubber bushings, bushing grooves and mounting bolt ends with Delco Silicone Lube or equivalent. 2. Install new bushings and sleeves in caliper ears. Position the sleeve so that the end toward the pad is flush with the machined surface of the ear. 3. Install retainer spring on back of inboard pad. 4. Position inboard pad with ears up and retainer spring facing the piston then press pad into piston bore until seated. a. Some inboard pads contain a wear sensor, the sensor should be toward the rear of the caliper when installed properly. 5. Position outboard pad to caliper interior with pad ears over caliper ears and tab at bottom of pad seated in caliper cutout. 6. With pads installed, install caliper as described under caliper installation. 7. Seat the outboard pad to the caliper by grasping the ears with channel locks and pressing together firmly, Fig. 3. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Rotor/Disc > Component Information > Technical Service Bulletins > Brakes - Rotor & Hub Flange Cleaning Tool Revision Brake Rotor/Disc: Technical Service Bulletins Brakes - Rotor & Hub Flange Cleaning Tool Revision File In Section: 5 - Brakes Bulletin No.: 73-50-37 Date: January, 1998 INFORMATION Subject: Revision to J 42450 Tool; Proper Brake Rotor and Hub Flange Surface Cleaning Models: 1998 and Prior Passenger Cars and Light Duty Trucks - with Disc Brakes (Rotor and Hub Separate) This bulletin is being revised to update the following text. This bulletin is being issued to inform the dealer about a revision to tool J 42450 and reinforce the need for proper hub flange and brake rotor mating surface cleaning during service. Tool J 42450 is a cleaning pad arbor and pad system that fits over the wheel stud and cleans the portion of the hub surface that is very difficult to reach with normal rotary cleaning pads. Tool J 42450 is being revised to J 42450-A to improve the hook and loop material retention. Any dealer experiencing problems with tool J 42450 should contact Kent-Moore at 1-800-345-2233 for a revised arbor at no charge. Anytime the brake rotor has been separated from the hub bearing flange or if rotor machining is necessary, the rotor and hub should be marked to maintain the original position. Clean the hub flange of all dirt and foreign material using special tool J 42450 or J 42450-A. Clean both sides of the brake rotor hub using an aggressive (80 grit) abrasive sanding pad on a rotary disc. Properly cleaning the rotor surfaces before rotor machining or reassembly ensures that dirt and corrosion will not add lateral runout to the rotor. Proper cleaning of the hub flange will also minimize the stack-up of lateral runout. On reassembly, the rotor should be reinstalled aligning the marks made on disassembly. Always use a torque wrench or the appropriate Torque Socket found in J 39544-KIT on an impact wrench when installing the wheel and tire assembly. Torque all wheel nuts using the correct sequence and torque. Refer to the Tire and Wheel Sub-Section in the applicable Service Manual. Excessive torque or torque variation between wheel nuts may cause distortion of the hub and rotor mating surface. This distortion may cause lateral runout and lead to brake pulsation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Rotor/Disc > Component Information > Technical Service Bulletins > Page 4978 Brake Rotor/Disc: Specifications Front Rotor Front Rotor Nominal Thickness 1.04 in Minimum Refinish Thickness .98 in Minimum Replacement Thickness .965 in Thickness Variation (Parallelism) .0005 in Runout (TIR) .003 in Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Rotor/Disc > Component Information > Service and Repair > Service Notes Brake Rotor/Disc: Service and Repair Service Notes Servicing of disc brakes is extremely critical due to the close tolerances required in machining the brake disc to insure proper brake operation. The maintenance of these close controls on the friction surfaces is necessary to prevent brake roughness. In addition, the surface finish must be non-directional and maintained at a micro-inch finish. This close control of the rubbing surface finish is necessary to avoid pulls and erratic performance and promote long lining life and equal lining wear of both left and right brakes. In light of the foregoing remarks, refinishing of the rubbing surfaces should not be attempted unless precision equipment, capable of measuring in micro-inches is available. To check runout of a disc, mount a dial indicator on a convenient part (steering knuckle, tie rod, disc brake caliper housing) so that the plunger of the dial indicator contacts the disc at a point one inch from the outer edge. If the total indicated runout exceeds specifications, install a new disc. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Disc Brake System > Brake Rotor/Disc > Component Information > Service and Repair > Service Notes > Page 4981 Brake Rotor/Disc: Service and Repair Front 1. Raise and support vehicle. 2. Remove tire and wheel assembly. 3. Remove caliper. 4. Remove grease cap from hub/rotor. 5. Remove cotter pin, nut and washer. 6. Remove hub/rotor from spindle, being careful not to damage spindle threads or outer bearing. 7. Reverse procedure to install, noting the following: a. Apply high-temperature wheel bearing grease to inner and outer wheel bearings. b. Torque nut to 12 ft. lbs. while turning wheel assembly forward by hand, back nut off one flat or until hole in spindle lines up with hole in nut, then insert cotter pin. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Backing Plate > Component Information > Testing and Inspection Backing Plate: Testing and Inspection Inspect backing plate shoe contact surface for grooves that may restrict shoe movement and cannot be removed by lightly sanding with emery cloth or other suitable abrasive. If backing plate exhibits above condition, it should be replaced. Also inspect for signs of cracks, warpage and excessive rust, indicating need for replacement. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Brake Drum > Component Information > Specifications Brake Drum: Specifications Original Diameter 9.50 in Maximum Refinish 9.56 in Discard 9.59 in Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Brake Drum > Component Information > Specifications > Page 4989 Brake Drum: Testing and Inspection Any time the brake drums are removed for brake service, the braking surface diameter should be checked with a suitable brake drum micrometer at several points to determine if they are within the safe oversize limit stamped on the brake drum outer surface. If the braking surface diameter exceeds specifications, the drum must be replaced. If the braking surface diameter is within specifications, drums should be cleaned and inspected for cracks, scores, deep grooves, taper, out of round and heat spotting. If drums are cracked or heat spotted, they must be replaced. Grooves and large scores can only be removed by machining with special equipment, as long as the braking surface is within specifications stamped on brake drum outer surface. Any brake drum sufficiently out of round to cause vehicle vibration or noise while braking, or showing taper should also be machined, removing only enough stock to true up the brake drum. After a brake drum is machined, wipe the braking surface diameter with a cloth soaked in denatured alcohol. Brake drums should always be machined in pairs and within allowable side to side specifications to maintain equal braking forces. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Brake Shoe > Component Information > Testing and Inspection Brake Shoe: Testing and Inspection Inspect brake linings for excessive wear, damage, oil, grease or brake fluid contamination. If any of the above conditions exists, brake linings should be replaced. Brake shoes should always be replaced as an axle set to maintain equal braking forces. Examine brake shoe webbing, hold-down and return springs for signs of overheating indicated by a slight blue color. If any component exhibits signs of overheating, replace hold-down and return springs with new ones. Overheated springs lose their pull and could cause brake linings to wear out prematurely. Inspect all springs for sags, bends and external damage, and replace as necessary. Inspect hold-down retainers and pins for bends, rust and corrosion. If any of the above conditions exist, replace retainers and pins. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Brake Shoe > Component Information > Testing and Inspection > Page 4993 Brake Shoe: Adjustments These brakes have self-adjusting shoe mechanisms that assure correct lining-to-drum clearances at all times. The automatic adjusters operate only when the brakes are applied as the vehicle is moving rearward or when the car comes to an uphill stop. Although the brakes are self-adjusting, an initial adjustment is necessary after the brake shoes have been relined or replaced, or when the length of the adjusting screw has been changed during some other service operation. Refer to COMPONENT REPLACEMENT AND REPAIR/DRUM BRAKES/REMOVAL/INSTALLATION for this procedure. Frequent usage of an automatic transmission forward range to halt reverse vehicle motion may prevent the automatic adjusters from functioning, thereby inducing low pedal heights. Should low pedal heights be encountered, it is recommended that numerous forward and reverse stops be made until satisfactory pedal height is obtained. If a low pedal condition cannot be corrected by making numerous reverse stops (provided the hydraulic system is free of air) it indicates that the self-adjusting mechanism is not functioning. Therefore it will be necessary to remove the brake drum, clean, free up and lubricate the adjusting mechanism. Then adjust the brakes, being sure the parking brake is fully released. 1. Using a suitable punch, knock out lanced area in backing plate or drum. If drum is installed on vehicle when this is done, remove drum and clean brake compartment of all metal. When adjustment is completed, a new hole cover must be installed in the backing plate. 2. Using suitable tool, turn brake adjusting screw to expand brake shoes at each wheel until wheel can just be turned by hand. Drag should be equal on all wheels. 3. Back off adjusting screw at each wheel 30 notches. 4. If shoe still drags slightly on drum, back off adjusting screw an additional one or two notches. 5. When adjusting screw has been backed off approximately 12 notches, brakes should be free of drag. Heavy drag at this point indicates tight parking brake cables. 6. Install adjusting hole cover in brake backing place. 7. Check parking brake for proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Wheel Cylinder > Component Information > Technical Service Bulletins > Brakes - Wheel Cylinder Inspection Guidelines Wheel Cylinder: Technical Service Bulletins Brakes - Wheel Cylinder Inspection Guidelines Bulletin No.: 03-05-24-001A Date: March 21, 2005 INFORMATION Subject: Service Information Regarding Rear Brake Drum Wheel Cylinder Inspections Models: 2005 and Prior GM Passenger Cars and Trucks 2005 and Prior Saturn Vehicles with Rear Drum Brakes Supercede: This bulletin is being revised add model years and include all GM vehicles. Please discard Corporate Bulletin Number 03-05-24-001 (Section 03 - Suspension). This bulletin provides information on proper inspection of rear drum brake wheel cylinders. Important: It is not recommended that dust boots be removed during inspection processes as dirt and debris could contaminate the wheel cylinder bore causing premature wear of the wheel cylinder. In addition, most bores should look damp and some lubricant may drip out from under the boot as a result of lubricant being present. All rear drum brake wheel cylinders are assembled with a lubricant to aid in assembly, provide an anti-corrosion coating to the cylinder bore, and lubricate internal rubber components. As a result of this lubrication process, it is not uncommon for some amount of lubricant to accumulate at the ends of the cylinder under the dust boot. Over time, the lubricant may work its way to the outside of the boot and cause an area of the boot to look damp. Evidence of a damp area on the boot does not indicate a leak in the cylinder. However, if there is excessive wetness (i.e. drips) coming from the boot area of the wheel cylinder, it could indicate a brake hydraulic fluid leak requiring wheel cylinder replacement. (Refer to the Wheel Cylinder Replacement procedures in the appropriate Service Manual.) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Wheel Cylinder > Component Information > Technical Service Bulletins > Page 4998 Wheel Cylinder: Specifications Wheel Cylinder Mounting Bolt 13 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Drum Brake System > Wheel Cylinder > Component Information > Technical Service Bulletins > Page 4999 Wheel Cylinder: Service and Repair Disassembled View Of Wheel Cylinder (typical) 1. Raise and support vehicle. 2. Remove wheel, drum and brake shoes. 3. Disconnect hydraulic line at wheel cylinder. 4. Remove wheel cylinder attaching screws, then remove wheel cylinder. 5. Strip cylinder of boots, pistons, springs and seals, Fig. 9. 6. Inspect cylinder bore for scoring and corrosion. Discoloration is a sign that springs have been damaged by heat, replace them if necessary. 7. Clean cylinder bore with crocus cloth. If cleaning does not remove scoring, replace cylinder. 8. Lubricate cylinder bore and seals with brake fluid, then reassemble cylinder. 9. Reverse procedure to install. Bleed system. Refer to Brakes / Service and Repair / Brake System Bleed. See: Service and Repair Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding With ABS System Fig. 59 EHCU/BPMV Module Bleeding MANUAL BLEEDING The Electro-Hydraulic Control Unit Brake Pressure Modulator Valve Module (EHCU/BPMV) should be bled after replacement or if air is trapped in the unit or system. If system bleeding is required, the module must be bled thoroughly before the wheel cylinders and calipers. There are two bleeders on top of the unit that appear to be normal bleeders (figure 221). These are modulator bleeders and must remain closed when the unit is not pressurized. The internal bleeders are on either side of EHCU/BPMV module. The valves are used to open the internal passages within the EHCU/BPMV module. Both bleed valves must be rotated 1/4 to 1/2 turn counterclockwise before beginning the bleed process. The valve on the lefthand side is used for the rear brakes and the valve on the righthand side is used for the front brakes. NOTE: The ignition switch must be in the Off position or false diagnostic trouble codes may be stored. SPECIAL TOOL REQUIRED (or equivalent) ^ J-39177, Combination valve pressure bleeding tool (three required). PROCEDURE 1. Install combination valve depressor tool J-39177 to LH high pressure accumulator bleed stem of EHCU/BPMV module. 2. Install combination valve depressor tool J-39177 to RH high pressure accumulator bleed stem of EHCU/BPMV module. 3. Install combination valve depressor tool J-39177 to rear combination valve. 4. Ensure master cylinder fluid level, fill if required. 5. Bleed EHCU/BPMV module as follows: a. Slowly depress brake pedal one time and hold. b. Open left modulator bleeder, until fluid flows clearly or pedal is depressed, the close left bleeder. c. Slowly release brake pedal. d. Wait 15 seconds, then repeat steps until all air is bled from EHCU/BPMV module. e. Close LH internal bleed valve. Torque bleed valve to 7 Nm (5 ft lbs). f. Repeat preceding bleed steps for righthand bleed procedure. g. Remove special tools. 6. Ensure master cylinder fluid level, fill if required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 5005 7. Bleed wheel cylinder and calipers. 8. Turn ignition key to On position, then perform 3 function test with TECH 1 scanner. 9. Check brake pedal feel and braking performance; repeat procedure if required. General Information The braking system can be bled manually or with pressure bleeding equipment. If bleeding manually, check fluid level frequently. Brake fluid should never be reused. Before driving the vehicle, check brake operation to ensure a firm pedal has been obtained. Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always seal and wipe off brake fluid containers to prevent spills. Manual Fig. 7 Caliper Bleeding Hose Installation 1. If vehicle is equipped with a vacuum or hydraulic booster, relieve system by applying brakes several times with engine off. 2. Fill master cylinder reservoir with DOT 3 brake fluid. Maintain full level during bleeding procedures. 3. If master cylinder is replaced or suspected to have air in the bore, bleed it before calipers. a. Disconnect forward brake pipe connection at master cylinder and allow brake fluid to flow from connector port, then reconnect pipe but do not tighten. b. Slowly apply brake pedal to allow air to bleed from loose fitting, then tighten fitting before releasing brake pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air has been purged from bore. d. After all air has been removed from forward pipe, repeat procedure for rear pipe. 4. If the vehicle is equipped with four wheel anti-lock brakes (4WAL), the Brake Pressure Modular Valve (BPMV) may need to be bled. If the BPMV has been replaced or is suspected of having air trapped inside, bleed system as outlined in "Anti-Lock Brakes chapter." 5. Bleed each wheel in the following sequence: a. Right rear. b. Left rear. c. Right front. d. Left front. 6. Attach a suitable hose to wheel caliper valve and immerse opposite end of hose into a suitable clean container partially filled with clean brake fluid , Fig. 7. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 5006 7. Slowly apply brake pedal one time and hold, loosen the bleeder valve to purge air from caliper, then tighten bleeder valve and release pedal. 8. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from caliper. 9. Repeat bleeding sequence at each wheel until system is bled. 10. Check brake pedal for "sponginess and brake warning lamp for an indication of unbalanced pressure. Repeat bleeding procedure to correct either of these conditions. Pressure Fig. 8 Plastic Reservoir Bleeder Adapter Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 5007 Fig. 9 Cast Iron Reservoir Bleeder Adapter Installation A diaphragm type pressure bleeder must be used. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. Also, adapters are needed depending on the type of master cylinder reservoir used on the vehicle: Brake Bleeder Adapter (Plastic Reservoir) tool No. J 29567, or equivalent, Fig.8. Brake Bleeder Adapter (Cast Iron Reservoir) tool No. J 23518-01, or equivalent, Fig. 9. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 5008 Fig. 10 Combination Valve Bleeding Tool Installation 1. Fill the pressure tank at least 2/3 full of brake fluid. Bleeder must be bled each time fluid is added. 2. Charge pressure bleeder to 20-25 psi. 3. Use tool No. J 39177, or equivalent, to depress and hold valve stem on combination valve, Fig. 10. 4. Install master cylinder adapter tool required for type of reservoir, then install bleeder hose to adapter 5. Bleed each wheel in the following sequence: a. Right rear. b. Left rear. c. Right front. d. Left front. 6. Open bleeder tank valve. 7. Attach a hose to caliper bleeder valve and immerse the opposite end of the hose into a suitable, clean, container, partially filled with clean brake fluid. 8. Open bleeder valve at least 3/4 turn and allow fluid to flow until no air is seen in fluid, then close valve. 9. Repeat procedure at each wheel. 10. Check brakes for "sponginess. Repeat bleeding procedure if necessary. 11. Remove pressure bleeder, adaptors, and tools, then fill reservoir to proper level. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Bleeding > System Information > Service and Repair > Hydraulic System Bleeding > Page 5009 Brake Bleeding: Service and Repair Master Cylinder Bleeding This procedure can be performed with master cylinder on or off vehicle. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. It is not necessary to bleed entire hydraulic system after replacing master cylinder, providing master cylinder has been bled and filled during installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Caliper > Component Information > Specifications Brake Caliper: Specifications Bleeder Valve 115 in.lb Brake Hose To Caliper Bolt 32 ft.lb Caliper Mounting Bolt 38 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Caliper > Component Information > Specifications > Page 5013 Brake Caliper: Description and Operation Fig. 4 Exploded View Of Disc Brake Caliper Assembly. The caliper assembly slides on its mounting surfaces, Fig. 4. Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboard side of the disc. This action causes the caliper assembly to slide until the outboard pad comes into contact with the disc, which in turn creates a slowing or stopping action. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Caliper > Component Information > Specifications > Page 5014 Brake Caliper: Testing and Inspection Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than .002 inch. If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Caliper > Component Information > Service and Repair > Removal/Installation Brake Caliper: Service and Repair Removal/Installation REMOVAL Fig. 2 Compressing Piston & Pad With C-clamp 1. Siphon enough brake fluid out of the master cylinder to bring fluid level to 1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore. 2. Raise and support vehicle, remove front wheels. 3. Using a C-clamp, as illustrated in Fig. 2, push piston back into its bore. 4. Remove two mounting bolts and lift caliper away from disc. INSTALLATION 1. Position caliper over disc, lining up mounting holes in caliper with holes in mounting bracket. If brake hose was not disconnected during removal, be sure not to kink it during installation. 2. Start mounting bolts through sleeves in inboard caliper ears and the mounting bracket, making sure ends of bolts pass under ears on inboard shoe. Right and left calipers must not be interchanged. 3. Push mounting bolts through to engage holes in the outboard ears. Then thread mounting bolts into bracket. 4. Torque mounting bolts to specifications. 5. If brake hose was removed, reconnect it and bleed the calipers. 6. Replace front wheels, lower vehicle and add brake fluid to master cylinder to bring level to 1/4 inch from top. Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Caliper > Component Information > Service and Repair > Removal/Installation > Page 5017 Brake Caliper: Service and Repair Disassembly/Inspection/Assembly DISASSEMBLY Fig. 4 Removing Piston From Caliper 1. Disconnect hose from the caliper being careful not to lose copper washers. 2. Remove caliper as outlined above. 3. Drain brake fluid from caliper. 4. Pad caliper interior with clean shop towels and apply compressed air to remove piston, Fig. 4. Use just enough air pressure to ease piston out of bore. When applying compressed air do not place fingers in front of piston in an attempt to catch or protect it as this could result in serious injury. 5. Carefully pry dust boot out of bore. 6. Using a small piece of wood or plastic, remove piston seal from bore. Do not use a metal tool of any kind to remove seal as it may damage bore. 7. Remove bleeder valve. INSPECTION Clean all parts in denatured alcohol, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than .002 inch. If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. ASSEMBLY Fig. 5 Installing Boot To Piston Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Caliper > Component Information > Service and Repair > Removal/Installation > Page 5018 Fig. 6 Installing Boot To Caliper 1. Lubricate caliper piston bore and new piston seal with clean brake fluid. Position seal in bore groove. 2. Lubricate piston with clean brake fluid and assemble a new boot into the groove in the piston so the fold faces the open end of the piston, Fig. 5. 3. Using care not to unseat the seal, insert piston into bore and force the piston to the bottom of the bore. 4. Position dust boot in caliper counterbore and install, Fig. 6. Check the boot installation to be sure the retaining ring molded into the boot is not bent and that the boot is installed below the caliper face and evenly all around. If the boot is not fully installed, dirt and moisture may enter the bore and cause corrosion. 5. If available, use new copper washers discarding the old washers and install the brake hose to the caliper. 6. Install pads and caliper assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Fluid > Component Information > Technical Service Bulletins > Brake Fluid - Level & Filling Recommendations Brake Fluid: Technical Service Bulletins Brake Fluid - Level & Filling Recommendations File In Section: 05 - Brakes Bulletin No.: 00-05-22-004 Date: May, 2000 INFORMATION Subject: Brake Fluid Level and Filling Recommendations Models: 2001 and Prior Passenger Cars and Trucks Many dealers and after-market repair shops advertise multi-point fluid "top-ups" in conjunction with oil changes or regular maintenance packages. These offers often include adding brake fluid to the master cylinder reservoir. There are only two reasons why the brake fluid level in the brake reservoir might go down. The first is that the brake fluid level goes down an acceptable level during normal brake lining wear. When the linings are replaced, the fluid will return to it's original level. The second possible reason for a low fluid level is that fluid is leaking out of the brake system. If fluid is leaking, the brake system requires repair and adding additional fluid will not correct the leak. If the system was properly filled during delivery of the vehicle, no additional fluid should be required under most circumstances between brake pad and/or shoe replacements. This information can be reinforced with the customer by referring them to the Brake Fluid section of their vehicle's Owner's Manual. Guidelines GM vehicles have incorporated a variety of brake fluid reservoir styles. The following guidelines are restricted to the plastic bodied fluid reservoirs and do not affect the original service recommendations for the older style metal bodied units. You may encounter both black plastic and translucent style reservoirs. You may have reservoirs with: ^ A MAX fill mark only ^ A MIN fill mark only ^ Both MAX and MIN marks The translucent style reservoirs do not have to have the covers removed in order to view the fluid level. It is a good practice not to remove the reservoir cover unless necessary to reduce the possibility of contaminating the system. Use the following guidelines to assist in determining the proper fluid level. Important: When adding brake fluid, use Delco Supreme II(R) Brake Fluid, GM P/N 12377967 or equivalent brand bearing the DOT-3 rating only. Important: At no time should the fluid level be allowed to remain in an overfilled condition. Overfilling the brake reservoir may put unnecessary stress on the seals and cover of the reservoir. Use the following guidelines to properly maintain the fluid level. If the reservoir is overfilled, siphon out the additional fluid to comply with the guidelines below. Important: If under any circumstance the brake fluid level is extremely low in the reservoir or the BRAKE warning indicator is illuminated, the brake system should be checked for leaks and the system repaired in addition to bringing the fluid level up to the recommended guidelines outlined below. A leaking brake system will have reduced braking performance and will eventually not work at all. Important: Some vehicles have reservoirs that are very sensitive to brake fluid levels and may cause the BRAKE indicator to flicker on turns as the fluid approaches the minimum required level. If you encounter a vehicle with this concern, increase the fluid level staying within the guidelines outlined below. ^ If the reservoir has a MAX level indicator, the reservoir should be returned to the MAX marking only at the time new brake pads and/or shoes are installed. If the reservoir fluid level is at the half-way point or above do not attempt to add additional brake fluid during routine fluid checks. ^ If the reservoir has both MAX and MIN indicators, the fluid level should be maintained above the MIN indicator during routine fluid checks and returned to the MAX indication only after new brake pads and/or shoes are installed. ^ For reservoirs with only a MIN indication, the fluid level should be maintained above the MIN indicator during routine fluid checks. Return the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Fluid > Component Information > Technical Service Bulletins > Brake Fluid - Level & Filling Recommendations > Page 5023 reservoir fluid level to full only after installing new brake pads and/or shoes. A full reservoir is indicated on translucent, snap cover reservoirs by a fluid level even with the top level of the view window imprinted into the side of the reservoir. On screw top models in black or translucent plastic, the full level is just below the bottom of the filler neck. Parts Information Part Number Description 12377967 Brake Fluid Parts are currently available from GMSPO. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Fluid > Component Information > Technical Service Bulletins > Page 5024 Brake Fluid: Specifications Brake System DOT 3 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Fluid Pressure Sensor/Switch > Component Information > Locations Brake Fluid Pressure Sensor/Switch: Locations Four-Wheel Antilock Brake Wiring, Engine Compartment On brake master cylinder Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Fluid Pressure Sensor/Switch > Component Information > Locations > Page 5028 C146, Brake Pressure Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Hose/Line > Component Information > Specifications Brake Hose/Line: Specifications Brake Hose To Rear Axle Bracket 13 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Proportioning/Combination Valve > Component Information > Specifications Brake Proportioning/Combination Valve: Specifications Combination Valve Bracket 21 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Proportioning/Combination Valve > Component Information > Specifications > Page 5035 Brake Proportioning/Combination Valve: Description and Operation These vehicles use either a two function or three function combination valve. Some vehicles use a height sensitive proportioning valve in addition to the combination valve. The two function combination valve consists of a metering valve and a brake failure warning switch. The hydraulic brake lines are routed through this valve to the wheel cylinders or calipers. The metering portion of this valve assists in providing balanced front to rear braking by delaying full hydraulic fluid pressure to the front disc brakes until the rear drum brakes overcome return spring tension and the linings contact the drums. The brake failure warning switch portion of the valve activates the brake warning lamp when there is a loss of pressure in either the front or the rear braking system. The three function combination valve consists of a metering valve, a brake failure warning switch, and a proportioning valve. The metering valve and brake failure warning switch operate the same as those in the two function combination valve previously described. The proportioning section of the valve proportions outlet pressure to the rear brakes after a certain rear input pressure has been reached, preventing rear wheel lock-up. The height sensitive proportioning valve provides ideal brake balance according to weight at rear axle. This valve is mounted on the frame and responds to changes in vehicle trim height in relation to rear axle load. Mechanical linkage connects the valve to a bracket attached to the rear axle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Proportioning/Combination Valve > Component Information > Specifications > Page 5036 Brake Proportioning/Combination Valve: Adjustments Fig. 9 Height Sensing Proportioning Valve Fig. 10 Adjustment Gauge Installation The height sensing proportioning valve must be adjusted whenever the valve and/or linkage is disassembled or removed for service. In addition, adjustment should be checked if excessive front wheel lock-up is experienced with a lower than desired brake application rate when vehicle is at or near maximum GVWR. 1. Raise and support vehicle leaving wheels on, and allow axle to hang free (no load condition). 2. Remove lever retaining nut and disconnect lever from valve shaft, Fig. 9. 3. Rotate valve shaft to permit installation of correct adjustment gauge, Fig. 10, ensuring that D shaped hole of gauge is properly seated on valve shaft and that gauge tang engages mounting hole in valve. Adjustment gauges vary depending upon vehicle application. Correct gauge must be used to ensure proper operation of braking system. 4. Install lever on valve shaft by pressing plastic bushing and clip assembly over shaft serrations using C-clamp or suitable pliers. Do not press lever onto shaft using retaining nut, as adjustment of valve will be disturbed. 5. Install lever retaining nut and torque to 70-98 inch lbs. 6. Cut tang off adjustment gauge and allow valve to rotate freely. 7. Lower vehicle and test brakes. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Hydraulic Control Assembly Antilock Brakes > Component Information > Service and Repair Hydraulic Control Assembly - Antilock Brakes: Service and Repair Fig. 222 Intermediate Shaft & Universal Joint Assembly. Fig. 223 EHCU/BPMV Replacement. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove steering column intermediate shaft as follows: WARNING: Refer to Air Bags and Seat Belts / Air Bags (Supplemental Restraint Systems) / Service and Repair / Air Bag System Disarming & Arming. See: Body and Frame/Interior Moulding / Trim/Dash Board / Instrument Panel/Air Bag(s) Arming and Disarming a. Set wheels in straight ahead position. b. Mark upper universal joint yoke to steering shaft and lower yoke to steering gear wormshaft for installation reference. c. Remove upper and lower universal pinch bolts, Fig. 222. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Hydraulic Control Assembly Antilock Brakes > Component Information > Service and Repair > Page 5040 d. Remove steering gear frame bolts, then lower the steering gear. e. Remove intermediate shaft and universal joint assembly. 2. Disconnect brake lines from bottom of combination valve. 3. Disconnect electrical connector from combination valve. 4. Remove master cylinder and combination valve assembly. 5. Remove brake lines from EHCU/BPMV module, then disconnect module electrical connectors. 6. Remove EHCU/BPMV bracket attaching nuts and bolt, Fig. 223. 7. Remove module and bracket assembly from vehicle, then the module from bracket assembly. 8. Reverse procedure to install, noting the following: a.a Torque module to bracket bolts to 5 ft. lbs. b. Torque bracket attaching bolt to 33 ft. lbs., then the two attaching nuts to 20 ft. lbs. c. Torque brake line fittings to module to 16 ft. lbs. d. Torque brake line fittings to combination valve to 15 ft. lbs. e. Install lower yoke onto steering gear wormshaft aligning marks made during removal. f. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. g. Raise steering gear into position while guiding upper yoke assembly onto steering shaft, align marks made during removal. h. Torque steering gear to frame bolts to 55 ft. lbs. i. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. j. Measure Cardan joint operating angle as shown in Fig. 222. Angle must be 34-39°. k. Bleed brake system and EHCU/BPMV module. See: Brake Bleeding Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Master Cylinder > Component Information > Specifications Brake Master Cylinder: Specifications Master Cylinder Mounting Nuts 21 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Master Cylinder > Component Information > Specifications > Page 5044 Brake Master Cylinder: Description and Operation Master Cylinder Some vehicles use a conventional tandem master cylinder with two hydraulic pistons operating in line. The primary piston controls the front brake system and the secondary piston controls the rear brake system. Other models use a master cylinder that operates the same as the conventional master cylinder, but also incorporates a quick take-up feature in the rear chamber to reduce excessive pedal travel which may result from increased fluid displacement required to move the low drag caliper piston out against the rotor. The quick take-up uses a spring-loaded ball check valve to hold pressure in the large diameter rear chamber when the brakes are first applied. At initial application, movement of the rear piston causes fluid to be displaced forward past the primary piston seal into the primary high pressure chamber. At a specified pressure, the ball unseats and fluid from the large rear bore is displaced past the bore into the reservoir. When the brake pedal is released, suction generated in the large bore chamber replenishes its fluid supply by drawing fluid from the reservoir around the quick take-up lip seal and through a small bleed orifice in the ball seat. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Master Cylinder > Component Information > Service and Repair > Bendix Type Master Cylinder Brake Master Cylinder: Service and Repair Bendix Type Master Cylinder Power Brake Systems 1. Disconnect all wire connectors from master cylinder components. 2. Disconnect brake lines from master cylinder. 3 Remove master cylinder mounting nuts, then the master cylinder. 4. Reverse procedure to install. Manual Brake Systems 1. Disconnect master cylinder pushrod from brake pedal. 2. Disconnect all wire connectors from master cylinder components. 3. Disconnect brake lines from master cylinder. 4. Remove master cylinder mounting nuts, then the master cylinder. 5. Reverse procedure to install. Disassembly/Assembly Fig. 6 Exploded View Of Master Cylinder. 1. Remove master cylinder from vehicle. 2. Clean outside of master cylinder, then remove reservoir cover and diaphragm. 3. Drain brake fluid from reservoir, then remove reservoir attaching bolts and reservoir. 4. Remove O-ring, compensating valve seals, valve poppets and springs. 5. Depress primary piston, then remove snap ring. 6. Remove primary piston assembly and piston return spring. 7. Remove secondary piston assembly by applying small amount of air pressure to front compensating valve port. Ensure front port is plugged. 8. Remove secondary spring. 9. Reverse procedure to assemble, noting the following: a. Inspect cylinder bore for scoring and corrosion. Replace master cylinder if necessary. b. Clean all metal parts in denatured alcohol. c. Clean all rubber parts in clean brake fluid. d. Polish discolored or stained cylinder with crocus cloth, then rinse in clean brake fluid. Ensure compensating port is clean. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Master Cylinder > Component Information > Service and Repair > Bendix Type Master Cylinder > Page 5047 Brake Master Cylinder: Service and Repair Delco Moraine Type Power Brake Systems 1. Disconnect all wire connectors from master cylinder components. 2. Disconnect brake lines from master cylinder. 3 Remove master cylinder mounting nuts, then the master cylinder. 4. Reverse procedure to install. Manual Brake Systems 1. Disconnect master cylinder pushrod from brake pedal. 2. Disconnect all wire connectors from master cylinder components. 3. Disconnect brake lines from master cylinder. 4. Remove master cylinder mounting nuts, then the master cylinder. 5. Reverse procedure to install. Composite Type Fig. 2 Exploded View Of Master Cylinder Disassembly 1. Remove master cylinder from vehicle. 2. Remove reservoir cover and diaphragm. Discard old brake fluid in reservoir. 3. Inspect cover and diaphragm. Replace if cut, cracked or deformed. 4. Remove fluid level switch and proportioner valve assembly, if equipped. 5. Depress primary piston and remove lock ring. 6. Plug primary fluid outlet (outlet nearest to cowl when master cylinder is installed), then apply compressed air into secondary fluid outlet to remove primary and secondary pistons. 7. Remove spring retainer and seals from secondary piston. 8. Clamp master cylinder in a vise, then remove reservoir using a pry bar. Remove reservoir grommets. 9. Inspect master cylinder bore for corrosion. Do not use abrasive material on master cylinder bore. Replace if bore is corroded. Assembly Clean all parts not included in repair kit with brake fluid. Do not dry with compressed air. Lubricate all rubber parts with clean brake fluid prior to installation. 1. Lubricate new reservoir grommets with silicone brake lube, then press grommets into master cylinder body. Ensure grommets are properly seated. 2. Lay reservoir upside down on flat, hard surface. Press master cylinder body onto reservoir using rocking motion. 3. Install new seals on secondary piston, then the spring retainer. 4. Install spring and secondary piston assembly into cylinder. 5. Install primary piston. Depress primary piston into cylinder, then install lock ring. 6. Install fluid level switch and proportioner valve assembly, if equipped. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Master Cylinder > Component Information > Service and Repair > Bendix Type Master Cylinder > Page 5048 7. Fit diaphragm into reservoir cover, then install cover onto reservoir. 8. Install master cylinder in vehicle. Cast Iron Type Fig. 4 Exploded View Of Master Cylinder. Fig. 5 Secondary Piston & Seals. Disassembly 1. Remove master cylinder from vehicle. 2. Clean outside of master cylinder, then remove reservoir cover and diaphragm. 3. Turn master cylinder over, then pump pushrod by hand to remove any remaining brake fluid. 4. Clamp master cylinder in a vise, with vise jaws gripping mounting flange and fluid ports pointing up. Do not clamp master cylinder body in vise. 5. Remove lock ring and primary piston assembly from cylinder bore. 6. Apply compressed air to secondary outlet port to remove secondary piston spring and retainer. 7. Using a 13/64 inch drill, enlarge hole in tube fitting insert of fluid outlet holes. Place a heavy washer over outlet hole, then thread a 1/4 X 20 X 3/4 screw into insert. Tighten screw until insert is unseated, then remove insert, screw and washer. 8. Remove primary and secondary seal from secondary piston. Inspection Clean all parts not included in repair kit with brake fluid. Do not dry with compressed air. 1. Inspect cylinder bore for scoring and corrosion. Replace master cylinder if necessary. 2. Polish discolored or stained cylinder with crocus cloth, then rinse in clean brake fluid. Ensure compensating port is clean. Assembly Lubricate all rubber parts with clean brake fluid prior to installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Brake Master Cylinder > Component Information > Service and Repair > Bendix Type Master Cylinder > Page 5049 1. With master cylinder in a vise, insert brass tube fitting inserts from overhaul kit into outlet holes. 2. Using spare brake line tube, thread tube nut into outlet hole and turn down until tube fitting insert bottoms into outlet hole. Remove tube nut and inspect outlet hole for burrs. 3. Install inner secondary seal into groove in secondary piston. 4. Install primary seal over end of secondary piston, with flat side of seal against flange of piston. 5. Install outer secondary seal into groove in end of secondary piston. 6. Install secondary piston spring retainer into secondary piston spring, then place the retainer and spring over end of secondary piston, with retainer seated inside lip of primary cup. 7. Hold master cylinder with open end down, then place secondary piston assembly into bore, with spring seated against end of bore. 8. Clamp master cylinder in a vise with open end of bore facing up. 9. Insert new primary piston assembly, spring end first, into bore. 10. Hold primary piston down, then install lock ring in groove on inside of bore. 11. Install new reservoir diaphragm into reservoir cover with beaded side out, then secure cover onto cylinder. 12. Install master cylinder in vehicle. Bleed brakes. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Wheel Cylinder > Component Information > Technical Service Bulletins > Brakes - Wheel Cylinder Inspection Guidelines Wheel Cylinder: Technical Service Bulletins Brakes - Wheel Cylinder Inspection Guidelines Bulletin No.: 03-05-24-001A Date: March 21, 2005 INFORMATION Subject: Service Information Regarding Rear Brake Drum Wheel Cylinder Inspections Models: 2005 and Prior GM Passenger Cars and Trucks 2005 and Prior Saturn Vehicles with Rear Drum Brakes Supercede: This bulletin is being revised add model years and include all GM vehicles. Please discard Corporate Bulletin Number 03-05-24-001 (Section 03 - Suspension). This bulletin provides information on proper inspection of rear drum brake wheel cylinders. Important: It is not recommended that dust boots be removed during inspection processes as dirt and debris could contaminate the wheel cylinder bore causing premature wear of the wheel cylinder. In addition, most bores should look damp and some lubricant may drip out from under the boot as a result of lubricant being present. All rear drum brake wheel cylinders are assembled with a lubricant to aid in assembly, provide an anti-corrosion coating to the cylinder bore, and lubricate internal rubber components. As a result of this lubrication process, it is not uncommon for some amount of lubricant to accumulate at the ends of the cylinder under the dust boot. Over time, the lubricant may work its way to the outside of the boot and cause an area of the boot to look damp. Evidence of a damp area on the boot does not indicate a leak in the cylinder. However, if there is excessive wetness (i.e. drips) coming from the boot area of the wheel cylinder, it could indicate a brake hydraulic fluid leak requiring wheel cylinder replacement. (Refer to the Wheel Cylinder Replacement procedures in the appropriate Service Manual.) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Wheel Cylinder > Component Information > Technical Service Bulletins > Page 5054 Wheel Cylinder: Specifications Wheel Cylinder Mounting Bolt 13 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Hydraulic System, Brakes > Wheel Cylinder > Component Information > Technical Service Bulletins > Page 5055 Wheel Cylinder: Service and Repair Disassembled View Of Wheel Cylinder (typical) 1. Raise and support vehicle. 2. Remove wheel, drum and brake shoes. 3. Disconnect hydraulic line at wheel cylinder. 4. Remove wheel cylinder attaching screws, then remove wheel cylinder. 5. Strip cylinder of boots, pistons, springs and seals, Fig. 9. 6. Inspect cylinder bore for scoring and corrosion. Discoloration is a sign that springs have been damaged by heat, replace them if necessary. 7. Clean cylinder bore with crocus cloth. If cleaning does not remove scoring, replace cylinder. 8. Lubricate cylinder bore and seals with brake fluid, then reassemble cylinder. 9. Reverse procedure to install. Bleed system. Refer to Brakes / Service and Repair / Brake System Bleed. See: Service and Repair Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Parking Brake System > Parking Brake Cable > Component Information > Testing and Inspection Parking Brake Cable: Testing and Inspection Inspect parking brake cable end for kinks, fraying and elongation, and replace as necessary. Use a small hose clamp to compress clamp where it enters backing plate to remove. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Parking Brake System > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations Fuse Block And Rear Body Harness Fuse Block And Rear Body Harness Below LH side of I/P, on park brake lower assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Parking Brake System > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch C255, Park Brake Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Parking Brake System > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch > Page 5065 Parking Brake Warning Switch: Diagrams Park Brake Warning Switch In-Line C225, Park Brake Warning Switch In-line C225, Park Brake Warning Switch In-line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Description and Operation Hydraulic Brake Booster: Description and Operation Fig. 1 Cross-sectional View Of Bendix Hydro-Boost Unit. In order to properly service power brake systems, a thorough understanding of the power assist system is necessary. These systems provide a mechanical assist, acting to increase the force applied to the master cylinder piston by the driver while decreasing the effort necessary to obtain acceptable stopping performance. Hydraulic assist units incorporate a basic open center spool valve, hydraulic cylinder and an accumulator assembly in a common housing. When the brake pedal is depressed, the hydraulic piston moves forward closing off fluid relief passages, the spool valve applies fluid pressure to the rear of the piston, and pressure applied to the piston is transmitted to the brake master cylinder through a pushrod. When the brake pedal is released, fluid pressure behind the piston is exhausted through the open center of the spool valve to a return line and the pump reservoir, and the spool valve diverts fluid pressure away from the hydraulic piston. The accumulator stores sufficient fluid under pressure to provide two or three power assisted stops in the event that pressure from the pump is interrupted. The design of the hydraulic cylinder allows the brakes to be applied without power assist, however, greater pedal effort is required to apply the brakes manually. The Hydro-Boost system, Fig. 1, provides an additional cylinder in the brake system. This cylinder contains no brake fluid. The Hydro-Boost cylinder is hydraulically operated, by pressurized fluid from the power steering pump, providing power assist to operate a dual master cylinder brake system. The booster is composed of two sections; the linkage section and the power section. The booster is designed so that if a total absence of power assist occurs, the brakes can be applied manually, but somewhat greater pressure on the brake pedal is required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Testing and Inspection > Slow Brake Pedal Return Hydraulic Brake Booster: Testing and Inspection Slow Brake Pedal Return 1. Excessive seal friction in booster. 2. Faulty spool action. 3. Restriction in return line from booster to pump reservoir. 4. Damaged input rod end. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Testing and Inspection > Slow Brake Pedal Return > Page 5072 Hydraulic Brake Booster: Testing and Inspection Grabby Brakes/ Booster Chatters/ Pedal Vibrates 1. Faulty spool action caused by contamination in system. 2. Power steering pump belts slip. 3. Low fluid level in power steering pump. 4. Faulty spool operation caused by contamination in system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Testing and Inspection > Slow Brake Pedal Return > Page 5073 Hydraulic Brake Booster: Testing and Inspection Accumulator Leak-Down/ System Does Not Hold Charge 1. Contamination in steering Hydro-Boost system. 2. Internal leakage in accumulator system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Service and Repair > General Service Information Hydraulic Brake Booster: Service and Repair General Service Information Certain general service procedures apply, regardless of whether the brakes are vacuum or hydraulically assisted. Only top quality, clean brake fluid should be used. More seals and valves are used with power brake systems than with ordinary brakes, so an inferior brake fluid will do much more damage. For the same reason, be sure all dirt is kept out of the system. Additionally, on models with hydraulic assist brakes, care must be taken not to mix the fluids of the booster hydraulic system and brake hydraulic system as the fluids are not compatible. If the power unit fails, the brakes will still operate, as the conventional brake system is left intact and a power unit is simply added to the existing system. Troubleshooting is then exactly the same up to the power unit. As with conventional hydraulic brakes, a spongy pedal with power brakes is caused by air in the system and grease on the linings will cause the brakes to grab. However, power brakes develop higher line pressure, thus making leaks more critical. Power units do not require adjustment. If there is a problem, the various valves and connections are simply replaced. The only exception is that the power units themselves sometimes have an adjustable connection to the brake pedal or linkage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Service and Repair > General Service Information > Page 5076 Hydraulic Brake Booster: Service and Repair Bendix Brake Boosters Hydro-Boost Assembly Fig. 2 Removing Accumulator Fig. 3 Typical Hydro-Boost Unit Disassembled DISASSEMBLY 1. Place accumulator compressor tool No. J-26889 or equivalent, around the end of accumulator, and install nut onto stud as shown in Fig. 2, then depress the accumulator with a C-clamp. 2. Remove retainer by using a suitable punch. 3. Release the C-clamp and remove accumulator compressor tool No. J-26889 or equivalent. 4. Remove accumulator, O-ring, retainer, plug and spring as shown in Fig. 3. 5. Remove retainer, output pushrod, baffle, piston return spring and retainer. 6. With a suitable saw, cut off the eyelet of the pedal rod, then remove the boot. 7. Remove nut, bracket and bolts, then separate cover from housing. 8. Remove piston assembly and seals. 9. Remove spool valve, then with a wire hook remove accumulator valve. 10. Remove return line fitting and seal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Service and Repair > General Service Information > Page 5077 Fig. 4 Spool valve inspection CLEANING/INSPECTION 1. Clean all parts in a suitable solvent being careful to avoid losing small parts. 2. Inspect valve spool and valve spool bore in booster housing for corrosion, nicks, scoring or other damage. Discoloration of the spool or bore, particularly in the grooves, is not harmful. 3. If the valve spool or the spool bore has nicks or scoring that can be felt with a fingernail, particularly on the hands, the spool and housing should be replaced as an assembly, Fig. 4. The clearance between the valve spool and the spool bore of the housing is important. Because of this, the spool and housing make are made as a selective assembly and therefore can only be replaced as an assembly. 4. Inspect the input rod and piston assembly for corrosion, nicks, scoring or excessive wear. If the piston is damaged, the input rod and piston assembly should be replaced. 5. Inspect piston bore in booster housing for corrosion, nicks, scoring or other damage. If the bore is damaged, the valve spool and housing should be replaced as an assembly. ASSEMBLY Lubricate all the seals and metal friction points with power steering fluid. 1. Install return line seal, then the fitting Fig. 3. 2. Install accumulator valve and spool valve into housing. 3. Install seal on piston assembly using seal protector tool No. J-25083 or equivalent. 4. Install seal onto the housing, then install cover and bolts. Torque housing bolts to 22 ft. lbs. 5. Install bracket and nut, then torque to 110 ft. lbs. 6. Install boot, output pushrod, baffle, piston return spring, and retainer using seal protector tool No. 2455l or equivalent. 7. Install retainer, spring, O-ring, and plug, using accumulator compressor tool No. J-26889 or equivalent, and C-clamp. 8. Depress the accumulator, then install the retainer and remove C-clamp. 9. Jam nut from the repair kit onto pedal rod, and install eyelet onto pedal rod. 10. Adjust eyelet to required length. Power Brake Unit, Remove 1. Disconnect master cylinder from power brake unit. 2. Disconnect power brake unit pushrod from brake pedal. 3. Remove power brake unit retaining nuts and the power brake unit. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Brake Booster > Component Information > Service and Repair > General Service Information > Page 5078 Hydraulic Brake Booster: Service and Repair Bleeding Brake Boosters (Bendix Type) 1. Fill oil reservoir to proper level and let stand at least two minutes. 2. Start engine and run momentarily. 3. Add oil as necessary. 4. Repeat above procedure until oil level remains constant after running engine. 5. Raise and support front of vehicle. 6. Turn wheels left and right, lightly contacting stops. 7. Add oil as necessary. 8. Lower vehicle. 9. Start engine and depress brake pedal several times while rotating steering wheel from stop to stop. 10. Turn engine off, then pump brake pedal four or five times to deplete accumulator pressure. 11. Check oil level, filling as necessary. 12. If oil is extremely foamy, allow vehicle to stand several minutes with engine off, then repeat entire procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Hydraulic Fluid Accumulator > Component Information > Service and Repair Hydraulic Fluid Accumulator: Service and Repair Fig. 2 Removing Accumulator Do not attempt to repair or apply heat to the accumulator. Before discarding an inoperative accumulator, drill a 1/16 inch diameter hole through the end of the accumulator pan. Do not drill through the piston end. Always wear safety glasses when performing service on the accumulator. 1. Push pedal rod several times to ensure accumulator is depleted. 2. Secure brake booster mounting bracket in a vise with pedal rod facing downward. 3. Place accumulator compressor tool No. J-26889 or equivalent, over master cylinder stud and install retaining nut. 4. Using a C-clamp, depress accumulator can, then insert a punch into hole in housing to unseat retaining ring, Fig. 2. Remove ring from housing using a small screwdriver. If accumulator cannot easily be depressed approximately .10 inch, the accumulator is still charged. This indicates an internal problem with the accumulator valves and the brake booster must be disassembled. 5. Slowly back off C-clamp until tension is relieved, then remove C-clamp, retaining cap and accumulator. 6. Reverse procedure to assemble. Lubricate accumulator can seal with power steering fluid. Ensure accumulator can retaining ring is completely seated in housing groove. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Description and Operation > General Description Vacuum Brake Booster: Description and Operation General Description In order to properly service power brake systems, a thorough understanding of the various power assist systems is necessary. These systems provide a mechanical assist, acting to increase the force applied to the master cylinder piston by the driver while decreasing the effort necessary to obtain acceptable stopping performance. Two basic types of power assist mechanisms are used: vacuum assist diaphragm assemblies which use engine vacuum and in some cases vacuum from an external vacuum pump, and hydraulic assist assemblies which use hydraulic pressure developed by an external pump (usually the power steering pump). Vacuum assist units are similar in operation, using vacuum applied to a diaphragm or piston in opposition to atmospheric pressure in order to increase the force applied to the master cylinder piston. However, two types of vacuum assist assemblies are used, the air suspended type and the vacuum suspended type. Air suspended units are under atmospheric pressure until the brakes are applied, then engine vacuum is admitted causing the piston or diaphragm to move and apply force to the master cylinder pushrod. Vacuum suspended types are balanced with engine vacuum until the brake pedal is depressed, allowing atmospheric pressure to unbalance the unit and apply force to the brake system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Description and Operation > General Description > Page 5086 Vacuum Brake Booster: Description and Operation Single Diaphragm Type Fig. 1 Exploded View Of Delco-Moraine Single Diaphragm Power Brake Unit Fig. 2 Exploded View Of Delco-Moraine Single Diaphragm Power Piston Assembly DESCRIPTION These power brake units, Figs. 1 and 2, are a combination vacuum-hydraulic brake booster of the vacuum suspended type which use engine intake manifold vacuum and atmospheric pressure for its power. These units consist of a vacuum power section and an hydraulic master cylinder section. The vacuum power section contains a power piston with rolling diaphragm mechanism and power piston return spring. The control valve is made up of an air valve and floating vacuum control valve assembly. The reaction mechanism consists of an hydraulic piston, reaction plate and a series of levers. The valve operating rod, which operates the air valve, projects from the power section and is connected to the brake pedal linkage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Description and Operation > General Description > Page 5087 The hydraulic pushrod operates against the master cylinder piston. A split system (tandem piston) type master cylinder is incorporated into some units. The front half of the master cylinder in the split system operates the rear brakes while the rear half of the master cylinder operates the front brakes. A vacuum check valve, attached to the front vacuum chamber and connected to the intake manifold, traps vacuum in the power unit at the highest level of vacuum. OPERATION As the brakes are applied by the driver, the valve operating rod and control piston move forward in the power piston assembly to compress the valve return spring and bring the poppet valve into contact with the vacuum valve seat in the valve housing to close the vacuum post. Any additional movement of the valve operating rod in the applied direction moves the control valve away from the poppet valve to open the atmospheric port and admit air through the air filter and passages to the chamber at the right of the vacuum power piston assembly. With vacuum on the left side of the diaphragm and atmospheric pressure on the right side of the diaphragm, a force is developed to move the vacuum power piston assembly, hydraulic pushrod, and hydraulic piston to the left to close the compensating port and force hydraulic fluid under pressure through the residual check valve and brake tubes into the brake wheel cylinders. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Description and Operation > General Description > Page 5088 Vacuum Brake Booster: Description and Operation Tandem Diaphragm Type Fig. 6 Exploded View Of Delco-Moraine Tandem Power Brake Unit Fig. 7 Exploded View Of Delco-Moraine Tandem Diaphragm Power Piston Assembly DESCRIPTION These units, Figs. 6 and 7, have a vacuum power chamber that consists of a front and rear shell, a housing divider, front and rear diaphragm and plate assemblies, an hydraulic pushrod and a diaphragm return spring. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Description and Operation > General Description > Page 5089 OPERATION As the brakes are applied by the driver, the valve operating rod and control piston move forward in the power piston assembly to compress the valve return spring and bring the poppet valve into contact with the vacuum valve seat in the valve housing to close the vacuum post. Any additional movement of the valve operating rod in the applied direction moves the control valve away from the poppet valve to open the atmospheric port and admit air through the air filter and passages to the chamber at the right of the vacuum power piston assembly. With vacuum on the left side of the diaphragm and atmospheric pressure on the right side of the diaphragm, a force is developed to move the vacuum power piston assembly, hydraulic pushrod, and hydraulic piston to the left to close the compensating port and force hydraulic fluid under pressure through the residual check valve and brake tubes into the brake wheel cylinders. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Testing and Inspection > Brakes Grab Vacuum Brake Booster: Testing and Inspection Brakes Grab 1. Faulty control valve. 2. Broken or damaged hydraulic brake lines. 3. Faulty master cylinder seals. 4. Cracked master cylinder casting. 5. Air in hydraulic system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Testing and Inspection > Brakes Grab > Page 5092 Vacuum Brake Booster: Testing and Inspection Hard Pedal 1. Internal vacuum leak. 2. Faulty control valve. 3. Broken or damaged hydraulic brake lines. 4. Collapsed or damaged vacuum hose. 5. Plugged or loose vacuum fitting. 6. Bad stud welds on front or rear housing on power head. 7. Faulty booster diaphragm. 8. Restricted air filter element. 9. Worn or distorted reaction plate or levers. 10. Cracked or broken power pistons or retainers. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Testing and Inspection > Brakes Grab > Page 5093 Vacuum Brake Booster: Testing and Inspection Slow or No Release 1. Faulty pushrod adjustment. 2. Binding linkage. 3. Blocked passage in power piston. 4. Air valve sticking shut. 5. Broken piston return spring or air valve spring. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Service and Repair > General Service Information Vacuum Brake Booster: Service and Repair General Service Information Certain general service procedures apply, regardless of whether the brakes are vacuum or hydraulically assisted. Only top quality, clean brake fluid should be used. More seals and valves are used with power brake systems than with ordinary brakes, so an inferior brake fluid will do much more damage. For the same reason, be sure all dirt is kept out of the system. Additionally, on models with hydraulic assist brakes, care must be taken not to mix the fluids of the booster hydraulic system and brake hydraulic system as the fluids are not compatible. If the power unit fails, the brakes will still operate, as the conventional brake system is left intact and a power unit is simply added to the existing system. Troubleshooting is then exactly the same up to the power unit. As with conventional hydraulic brakes, a spongy pedal with power brakes is caused by air in the system and grease on the linings will cause the brakes to grab. However, power brakes develop higher line pressure, thus making leaks more critical. Power units do not require adjustment. If there is a problem, the various valves and connections are simply replaced. The only exception is that the power units themselves sometimes have an adjustable connection to the brake pedal or linkage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Service and Repair > General Service Information > Page 5096 Vacuum Brake Booster: Service and Repair Booster Assembly Single Diaphragm Type Fig. 3 Exploded View Of Delco-Moraine Single Diaphragm Brake Booster Components Fig. 4 Brake Booster Holding Fixture DISASSEMBLY 1. Remove boot, silencer, vacuum check valve, grommet and front housing seal, Fig. 3. 2. Scribe a line across front and rear housing, then mount brake booster to brake mounting fixture tool No. J 23456 or equivalent, Fig. 4. 3. Turn fixture handle counterclockwise to unlock housings. 4. Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 3. 5. Remove reaction body retainer, piston rod, reaction retainer and filter, Fig. 3. 6. Remove power piston and pushrod assembly as follows: a. While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm, Fig. 3. b. Use a slight force to dislodge diaphragm retainer, Fig. 3. 7. Remove diaphragm from diaphragm support, Fig. 3. 8. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary. 9. Clean all parts in denatured alcohol. Dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Service and Repair > General Service Information > Page 5097 Fig. 5 Brake Booster Lock Tab & Staking Positions ASSEMBLY 1. Lubricate inside diameter of diaphragm lip with a thin layer of silicone grease, then install diaphragm into the diaphragm support, Fig. 3. 2. Install diaphragm and diaphragm support onto power piston and pushrod assembly. 3. Install new diaphragm retainer. Ensure retainer is fully seated. 4. Install filter, reaction retainer, piston rod and reaction body retainer. 5. Apply silicone grease to the power piston bearing and install it into the rear housing, then install return spring. 6. Mount housings to holding fixture and turn fixture handle in a clockwise direction to lock the front and rear housings. 7. Stake housing in locations shown, Fig. 5. Do not stake a tab that has been staked previously. 8. Lubricate inside and outside edges of grommet and front housing seal, then install grommet and seal. 9. Install vacuum check valve, silencer and boot. 10. Ensure piston rod depth is within specifications using gauge tool No. J-37839 or equivalent. Tandem Diaphragm Type Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Service and Repair > General Service Information > Page 5098 Fig. 8 Exploded View Of Delco-Moraine Tandem Diaphragm Brake Booster Components Brake Booster Holding Fixture DISASSEMBLE 1. Remove boot, silencer, vacuum check valve, grommet and front housing seal, Fig. 8. 2. Scribe a line across front and rear housing, then install brake booster to brake mounting fixture tool No. J-23456 or equivalent, Fig. 6. 3. Turn fixture handle to unlock housings. 4. Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 8. 5. Remove piston rod, reaction retainer and power head silencer. 6. Remove power piston and pushrod assembly as follows: a. While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm. b. Use a slight force to dislodge diaphragm retainer. 7. Remove primary diaphragm and primary support plate from housing divider. 8. Remove primary diaphragm from primary support plate. 9. Remove secondary diaphragm and secondary support plate from housing divider. 10. Remove secondary piston bearing from housing divider. 11. Remove secondary diaphragm from secondary support plate. 12. Remove reaction body retainer, reaction body, reaction disc and reaction piston from reaction body. 13. Remove air valve spring and reaction bumper from end of air valve pushrod. 14. Remove retaining ring from air valve pushrod assembly. 15. Remove air valve pushrod assembly by inserting a screwdriver through the pushrod eyelet and pulling pushrod assembly straight out. 16. Remove filter, retainer and O-ring from air valve pushrod assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Service and Repair > General Service Information > Page 5099 17. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary. 18. Clean all parts in denatured alcohol and dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol. Brake Booster Lock Tab & Staking Positions ASSEMBLE 1. Install lubricated O-ring onto air valve pushrod assembly. 2. Install air valve pushrod into the power piston. 3. Install retainer and seat. 4. Install filter over pushrod eyelet and into power piston. 5. Install retaining ring onto air valve pushrod assembly. 6. Install reaction bumper, air valve spring, reaction piston and reaction disc onto reaction body. 7. Install reaction body, then reaction body retainer. 8. Lubricate inside diameter of secondary diaphragm lip, inside diameter of primary diaphragm lip and the secondary piston bearing with a thin layer of silicone grease. 9. Install secondary diaphragm into the secondary support plate, Fig. 8. 10. Install secondary diaphragm and secondary support plate over the power piston and pushrod assembly. 11. Install secondary piston bearing into housing divider with flat surface of bearing on the same side as the six raised lugs on the divider. 12. Install secondary piston bearing and housing divider over power piston assembly and pushrod. 13. Install primary diaphragm into the primary support plate, Fig. 8. 14. Fold primary diaphragm up away from the primary support plate, then install primary diaphragm and support plate over power piston and pushrod assembly. 15. Fold primary diaphragm back into position and pull the outside edge of diaphragm over formed flange of housing divider. 16. Install new diaphragm retainer. Ensure retainer is fully seated. 17. Install silencer, reaction retainer and piston rod. 18. Lubricate inside and outside diameters of primary piston bearings with silicone grease. 19. Install primary piston bearing into rear housing. 20. Install power piston assembly into rear housing, then the return spring. 21. Mount housing to holding fixture and turn fixture handle to lock the front and rear housings, Fig. 6. 22. Stake housing in locations shown, Fig. 7. Do not stake a tab that has been staked previously. 23. Lubricate inside and outside edges of grommet and front housing seal, then install grommet and seal. 24. Install vacuum check valve, silencer and boot. 25. Ensure piston rod depth is within specifications using gauge tool No. J-37839 or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Brake Booster > Component Information > Service and Repair > General Service Information > Page 5100 Vacuum Brake Booster: Service and Repair Power Brake Unit 1. Disconnect master cylinder from power brake unit. 2. Disconnect power brake unit pushrod from brake pedal. 3. Remove power brake unit retaining nuts and the power brake unit. 4. Reverse procedure to install. Torque master cylinder retaining nuts to specification. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > ABS Main Relay > Component Information > Locations ABS Main Relay: Locations Fig. 223 EHCU/BPMV Replacement. The relay is located inside the Brake Pressure Modulator Valve (BPMV). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > Brake Fluid Pump Relay > Component Information > Locations Brake Fluid Pump Relay: Locations Fig. 223 EHCU/BPMV Replacement. The relay is located inside the Brake Pressure Modulator Valve (BPMV). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations Electronic Brake Control Module: Locations Four-Wheel Antilock Brake Wiring, Engine Compartment Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 5111 Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 5112 C181, 4WAL EHCU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 5113 Electronic Brake Control Module: Service and Repair Fig. 222 Intermediate Shaft & Universal Joint Assembly. Fig. 223 EHCU/BPMV Replacement. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove steering column intermediate shaft as follows: WARNING: Refer to Air Bags and Seat Belts / Air Bags (Supplemental Restraint Systems) / Service and Repair / Air Bag System Disarming & Arming. See: Body and Frame/Interior Moulding / Trim/Dash Board / Instrument Panel/Air Bag(s) Arming and Disarming a. Set wheels in straight ahead position. b. Mark upper universal joint yoke to steering shaft and lower yoke to steering gear wormshaft for installation reference. c. Remove upper and lower universal pinch bolts, Fig. 222. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations > Page 5114 d. Remove steering gear frame bolts, then lower the steering gear. e. Remove intermediate shaft and universal joint assembly. 2. Disconnect brake lines from bottom of combination valve. 3. Disconnect electrical connector from combination valve. 4. Remove master cylinder and combination valve assembly. 5. Remove brake lines from EHCU/BPMV module, then disconnect module electrical connectors. 6. Remove EHCU/BPMV bracket attaching nuts and bolt, Fig. 223. 7. Remove module and bracket assembly from vehicle, then the module from bracket assembly. 8. Reverse procedure to install, noting the following: a.a Torque module to bracket bolts to 5 ft. lbs. b. Torque bracket attaching bolt to 33 ft. lbs., then the two attaching nuts to 20 ft. lbs. c. Torque brake line fittings to module to 16 ft. lbs. d. Torque brake line fittings to combination valve to 15 ft. lbs. e. Install lower yoke onto steering gear wormshaft aligning marks made during removal. f. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. g. Raise steering gear into position while guiding upper yoke assembly onto steering shaft, align marks made during removal. h. Torque steering gear to frame bolts to 55 ft. lbs. i. Install pinch bolt, making sure bolt passes through shaft undercut, then torque bolt to 30 ft. lbs. j. Measure Cardan joint operating angle as shown in Fig. 222. Angle must be 34-39°. k. Bleed brake system and EHCU/BPMV module. See: Brake Bleeding Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Brake Fluid Pressure Sensor/Switch > Component Information > Locations Brake Fluid Pressure Sensor/Switch: Locations Four-Wheel Antilock Brake Wiring, Engine Compartment On brake master cylinder Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Brake Fluid Pressure Sensor/Switch > Component Information > Locations > Page 5119 C146, Brake Pressure Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations Fuse Block And Rear Body Harness Fuse Block And Rear Body Harness Below LH side of I/P, on park brake lower assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch C255, Park Brake Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch > Page 5125 Parking Brake Warning Switch: Diagrams Park Brake Warning Switch In-Line C225, Park Brake Warning Switch In-line C225, Park Brake Warning Switch In-line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Locations > LH Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Locations > LH > Page 5130 Four Wheel Antilock Front Brake Sensors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Diagrams > RH Wheel Speed Sensor: Diagrams RH C189, RH Front Wheel Sensor C189, RH Front Wheel Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Diagrams > RH > Page 5133 Wheel Speed Sensor: Diagrams LH C190, LH Front Wheel Sensor C190, LH Front Wheel Sensor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Service and Repair > Front Wheel Speed Sensor Wheel Speed Sensor: Service and Repair Front Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. Remove hub and rotor assembly. 4. Disconnect wheel sensor electrical connector. 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Service and Repair > Front Wheel Speed Sensor > Page 5136 Wheel Speed Sensor: Service and Repair Rear Wheel Speed Sensor Fig. 58 Rear Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Remove brake drum. 3. Remove primary brake shoe. 4. Disconnect sensor electrical connector. 5. Remove sensor wire from rear axle clip. 6. Remove speed sensor attaching bolts, Fig. 58, then remove sensor by pulling wire through hole in backing plate. 7. Reverse procedure to install. Torque speed sensor attaching bolts to 26 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5143 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5144 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5145 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5146 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5147 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5148 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5149 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5150 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5151 Neutral Safety Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5152 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5153 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5154 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5155 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5156 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5157 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5158 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5159 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5160 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5161 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5162 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5163 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5164 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5165 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5166 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5167 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5168 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5169 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5170 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5171 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5172 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5173 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Page 5174 Neutral Safety Switch: Service and Repair Fig. 13 Neutral Safety & Back-up Lamp Switch Replacement REMOVAL 1. Disconnect battery ground cable. 2. Disconnect switch electrical connector from switch terminals, Fig. 13. 3. Remove switch from steering column jacket. INSTALLATION 1. Place gear selector in Neutral position. 2. Align actuator on switch with hole in the shift tube, Fig. 13. 3. Position rearward side of switch (connector side) to fit into cutout in the lower shift bowl. 4. Push down on front of switch. Tangs on housing back will snap into place in rectangular holes in the shift bowl. 5. Connect switch electrical connector, then the battery ground cable. 6. Adjust switch by moving the gear selector to Park position. The main housing and housing back should ratchet, providing proper switch adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Locations > Engine Ground Cable Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Locations > Engine Ground Cable > Page 5180 Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Locations > Engine Ground Cable > Page 5181 Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions Battery Cable: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5184 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5185 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5186 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5187 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5188 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5189 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5190 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5191 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5192 Battery Cable: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5193 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5194 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5195 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5196 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5197 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5198 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5199 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5200 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5201 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5202 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5203 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5204 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5205 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5206 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5207 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5208 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5209 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5210 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5211 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5212 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5213 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5214 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Battery > Battery Cable > Component Information > Diagrams > Diagram Information and Instructions > Page 5215 C198, Battery Cable Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Tools - Released for CS Generator Diagnosis Alternator: Technical Service Bulletins Tools - Released for CS Generator Diagnosis File In Section: 6 - Engine Bulletin No.: 83-64-09 Date: March, 1998 INFORMATION Subject: New Tool J 41450-B, Released for CS Generator Diagnosis Models: 1988-98 Passenger Cars and Light Trucks with CS-Series Generators A new CS-Series Generator Tester, J 41450-B, has been sent to all dealers as part of the Essential Tool Package. This tool will work on all CS-Series generators for past model years. The tool is shown in Figure 1. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Tools - Released for CS Generator Diagnosis > Page 5221 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Tools - Released for CS Generator Diagnosis > Page 5222 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Tools - Released for CS Generator Diagnosis > Page 5223 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Tools - Released for CS Generator Diagnosis > Page 5224 Generator Not Operating Properly The charts shown can be used in place of the diagnostic procedures in previous Service Manuals when this new tool is used. This information will be included in the 1999 Service Manual. Inspect the following before testing the generator: ^ The battery. Make sure the vehicle battery is in good condition and fully charged. Refer to Battery Load Test. ^ The built in hydrometer in the battery. The green eye must be showing in the hydrometer. ^ The voltage across the battery terminals with all the loads OFF should be above 12 V. Refer to Battery Load Test. ^ Make sure the battery connections are clean and tight. ^ The drive belt for damage or looseness. ^ The wiring harness at the generator. Make sure the harness connector is tight and latched. Make sure the output terminal of the generator is connected to the vehicle battery (positive) generator lead. ^ All the charging system related fuses and electrical connections for damage or looseness. Refer to the starter and charging system schematics. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Page 5225 Alternator: Specifications Model ................................................................................................................................................... .................................................................... 1101617 Rated Hot Output, Amps ..................................................................................................................... ............................................................................. 100 Model ................................................................................................................................................... .................................................................... 1101637 Rated Hot Output, Amps ..................................................................................................................... ............................................................................. 105 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Page 5226 Alternator: Locations Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Page 5227 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Technical Service Bulletins > Page 5228 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions Alternator: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5231 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5232 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5233 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5234 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5235 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5236 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5237 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5238 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5239 Alternator: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5240 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5241 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5242 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5243 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5244 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5245 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5246 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5247 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5248 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5249 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5250 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5251 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5252 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5253 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5254 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5255 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5256 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5257 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5258 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5259 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5260 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5261 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Diagram Information and Instructions > Page 5262 Alternator: Connector Views C102, Generator C102, Generator Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Page 5263 Alternator: Application and ID Engine ................................................................................................................................................. .............................................................................. All Alternator Model .............................................. ....................................................................................................................................................... CS-130D Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Page 5264 Alternator: Description and Operation Fig. 1 Delcotron Type CS-130 & CS-144 Alternators. These units feature a high ampere output-to-weight ratio. The Delcotron CS-130 & CS-144 alternators are electrically similar to standard units, however, they do not contain a diode trio. The voltage setting of the integral regulator varies with temperature and limits system voltage by controlling rotor field current. The regulator has four terminals; "P," "L," "I," and "S." The "P" terminal is not used. The "L" terminal may be connected to the instrument cluster for charging indicator and voltmeter. The "I" terminal provides a voltage feed for the heated oxygen sensor, variable throttle control relay, and electronic automatic transmission. The "S" terminal is not used. The alternator is serviceable only by complete replacement only. No periodic maintenance is required. It should not be disassembled for any reason. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Charging System > Alternator > Component Information > Diagrams > Page 5265 Alternator: Service and Repair GENERATOR REPLACEMENT Removal 1. Remove negative battery cable. 2. Remove engine cover from inside the vehicle. 3. Remove air cleaner inlet hose. The power steering reservoir may need to be unbolted and set aside for access. 4. Remove drive belt. 5. Disconnect electrical connector from the regulator. 6. Remove lower left mounting stud and nut. 7. Remove lower right mounting bolt and nut. 8. Remove upper dipstick tube for access. 9. Remove rear mounting bolt. 10. Remove nut at the BAT terminal. 11. Remove generator from the vehicle. Installation 1. Install generator to the vehicle. 2. Install nut at the BAT terminal. 3. Install lower left mounting stud and nut. 4. Install lower right mounting bolt and nut. 5. Install rear mounting bolt. Tighten nut at the BAT terminal to 6 Nm (53 lbs.in.). Stud to 25 Nm (18 lbs.ft.). Nut to 25 Nm (18 lbs.ft.). Bolt to 25 Nm (18 lbs.ft.). 6. Connect electrical connector to the regulator. 7. Install upper dipstick tube. 8. Install drive belt. 9. Install air cleaner duct. 10. Install power steering reservoir (if removed for access). 11. Install engine cover. 12. Connect negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information Key: Technical Service Bulletins Locks - Key Code Security Rules and Information INFORMATION Bulletin No.: 10-00-89-010 Date: May 27, 2010 Subject: Key Code Security Rules and Information on GM KeyCode Look-Up Application (Canada Only) Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saturn and Saab 2002 and Prior Isuzu Attention: This bulletin has been created to address potential issues and questions regarding KeyCode security. This bulletin should be read by all parties involved in KeyCode activity, including dealer operator, partner security coordinator, sales, service and parts departments. A copy of this bulletin should be printed and maintained in the parts department for use as a reference. Important U.S. dealers should refer to Corporate Bulletin Number 10-00-89-009. Where Are Key Codes Located? General Motors provides access to KeyCodes through three sources when a vehicle is delivered to a dealer. Vehicle KeyCodes are located on the original vehicle invoice to the dealership. There is a small white bar coded tag sent with most new vehicles that also has the key code printed on it. Dealerships should make a practice of comparing the tag's keycode numbers to the keycode listed on the invoice. Any discrepancy should be reported immediately to the GM of Canada Key Code Inquiry Desk. Remember to remove the key tag prior to showing vehicles to potential customers. The third source for Key codes is through the GM KeyCode Look-Up feature within the OEConnection D2DLink application. KeyCode Look-Up currently goes back 17 previous model years from the current model year. When a vehicle is received by the dealership, care should be taken to safeguard the original vehicle invoice and KeyCode tag provided with the vehicle. Potential customers should not have access to the invoice or this KeyCode tag prior to the sale being completed. After a sale has been completed, the KeyCode information belongs to the customer and General Motors. Tip Only the original invoice contains key code information, a re-printed invoice does not. GM KeyCode Look-Up Application for GM of Canada Dealers All dealers should review the General Motors of Canada KeyCode Look-Up Policies and Procedures (Service Policy & Procedures Manual Section 3.1.6 "Replacement of VIN plates & keys"). Please note that the KeyCode Access site is restricted. Only authorized users should be using this application. Please see your Parts Manager for site authorized users. KeyCode Look-Up currently goes back 17 years from current model year. Important notes about security: - Users may not access the system from multiple computers simultaneously. - Users may only request one KeyCode at a time. - KeyCode information will only be available on the screen for 2 minutes. - Each user is personally responsible for maintaining and protecting their password. - Never share your password with others. - User Id's are suspended after 6 consecutive failed attempts. - User Id's are disabled if not used for 90 days. - Processes must be in place for regular dealership reviews. - The Parts Manager (or assigned management) must have processes in place for employee termination or life change events. Upon termination individuals access must be turned off immediately and access should be re-evaluated upon any position changes within the dealership. - If you think your password or ID security has been breached, contact Dealer Systems Support at 1-800-265-0573. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information > Page 5271 Each user will be required to accept the following agreement each time the KeyCode application is used. Key Code User Agreement - Key codes are proprietary information belonging to General Motors Corporation and to the vehicle owner. - Unauthorized access to, or use of, key code information is unlawful and may subject the user to criminal and civil penalties. - This information should be treated as strictly confidential and should not be disclosed to anyone unless authorized. I will ensure that the following information is obtained prior to releasing any Key Code information: 1. Government issued picture ID (Drivers License) 2. Registration or other proof of ownership. Registration should have normal markings from the Province that issued the registration and possibly the receipt for payment recorded as well. Important - GM takes this agreement seriously. Each user must be certain of vehicle ownership before giving out key codes. - When the ownership of the vehicle is in doubt, dealership personnel should not provide the information. Key code requests should never be received via a fax or the internet and key codes should never be provided to anyone in this manner. A face to face contact with the owner of the vehicle is the expected manner that dealers will use to release a key code or as otherwise stipulated in this bulletin or other materials. - Key codes should NEVER be sent via a fax or the internet. - Each Dealership should create a permanent file to document all KeyCode Look Up transactions. Requests should be filed by VIN and in each folder retain copies of the following: - Government issued picture ID (Drivers License) - Registration or other proof of ownership. - Copy of the paid customer receipt which has the name of the employee who cut and sold the key to the customer. - Do not put yourself or your Dealership in the position of needing to "explain" a KeyCode Look Up to either GM or law enforcement officials. - Dealership Management has the ability to review all KeyCode Look-Up transactions. - Dealership KeyCode documentation must be retained for two years. Frequently Asked Questions (FAQs) for GM of Canada Dealers How do I request a KeyCode for customer owned vehicle that is not registered? Scrapped, salvaged or stored vehicles that do not have a current registration should still have the ownership verified by requesting the vehicle title, current insurance policy and / or current lien holder information from the customers financing source. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. In these cases, a short description of the vehicle (scrapped, salvaged, etc.) and the dealership location should be kept on file. Any clarifying explanation should be entered into the comments field. How do I document a KeyCode request for a vehicle that is being repossessed? The repossessor must document ownership of the vehicle by providing a court ordered repossession order and lien-holder documents prior to providing key code information. Copies of the repossessors Drivers License and a business card should be retained by the dealership for documentation. What do I do if the registration information is locked in the vehicle? Every effort should be made to obtain complete information for each request. Each Dealership will have to decide on a case by case basis if enough information is available to verify the customer's ownership of the vehicle. Other forms of documentation include vehicle title, insurance policy, and or current lien information from the customers financing source. Dealership Management must be involved in any request without complete information. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. Can I get a print out of the information on the screen? It is important to note that the Key Code Look Up Search Results contain sensitive and/or proprietary information. For this reason GM recommends against printing it. If the Search Results must be printed, store and/or dispose of the printed copy properly to minimize the risk of improper or illegal use. Who in the dealership has access to the KeyCode application? Dealership Parts Manager (or assigned management) will determine, and control, who is authorized to access the KeyCode Look Up application. However, we anticipate that dealership parts and service management will be the primary users of the application. The KeyCode Look Up application automatically tracks each user activity session. Information tracked by the system includes: User name, User ID, all other entered data and the date/time of access. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information > Page 5272 What if I input the VIN incorrectly? If an incorrect VIN is entered into the system (meaning that the system does not recognize the VIN or that the VIN has been entered incorrectly) the system will return an error message. If I am an authorized user for the KeyCode application, can I access the application from home? Yes. What if I suspect key code misuse? Your dealership should communicate the proper procedures for requesting key codes. Any suspicious activity either within the dealership or externally should be reported to Dealer Systems Support at 1-800-265-0573 or GM of Canada Key Code Inquiry Desk at 1-905-644-4892. Whose key codes can I access through the system? At this time the following Canadian vehicle codes are available through the system: Chevrolet, Cadillac, Buick, Pontiac, GMC, HUMMER (H2 and H3 only), Oldsmobile, Saturn, Saab and Isuzu (up to 2002 model year) for a maximum of 17 model years. What should I do if I enter a valid VIN and the system does not produce any key code information? Occasionally, the KeyCode Look Up application may not produce a key code for a valid VIN. This may be the result of new vehicle information not yet available. In addition, older vehicle information may have been sent to an archive status. If you do not receive a key code returned for valid VIN, you should contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. How do I access KeyCodes if the KeyCode Look-up system is down? If the KeyCode Look-up system is temporarily unavailable, you can contact the original selling dealer who may have it on file or contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the customer is dealing with an emergency lock-out situation, you need to have the customer contact Roadside assistance, OnStar if subscribed, or 911. What should I do if the KeyCode from the look-up system does not work on the vehicle? On occasion a dealer may encounter a KeyCode that will not work on the vehicle in question. In cases where the KeyCode won't work you will need to verify with the manufacturer of the cutting equipment that the key has been cut correctly. If the key has been cut correctly you may be able to verify the proper KeyCode was given through the original selling dealer. When unable to verify the KeyCode through the original selling dealer contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the key has been cut correctly and the code given does not work, the lock cylinder may have been changed. In these situations following the proper SI document for recoding a key or replacing the lock cylinder may be necessary. How long do I have to keep KeyCode Records? Dealership KeyCode documentation must be retained for two years. Can I get a KeyCode changed in the Look-Up system? Yes, KeyCodes can be changed in the Look-Up system if a lock cylinder has been changed. Contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. What information do I need before I can provide a driver of a company fleet vehicle Keys or KeyCode information? The dealership should have a copy of the individual's driver's license, proof of employment and registration. If there is any question as to the customer's employment by the fleet company, the dealer should attempt to contact the fleet company for verification. If there is not enough information to determine ownership and employment, this information should not be provided. How do I document a request from an Independent Repair facility for a KeyCode or Key? The independent must provide a copy of their driver's license, proof of employment and signed copy of the repair order for that repair facility. The repair order must include customer's name, address, VIN, city, province and license plate number. Copies of this information must be included in your dealer KeyCode file. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information > Page 5273 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5278 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5279 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5280 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5281 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5282 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5283 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5284 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5285 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5286 Neutral Safety Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5287 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5288 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5289 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5290 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5291 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5292 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5293 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5294 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5295 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5296 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5297 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5298 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5299 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5300 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5301 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5302 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5303 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5304 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5305 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5306 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5307 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 5308 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Neutral Safety Switch > Component Information > Diagrams > Page 5309 Neutral Safety Switch: Service and Repair Fig. 13 Neutral Safety & Back-up Lamp Switch Replacement REMOVAL 1. Disconnect battery ground cable. 2. Disconnect switch electrical connector from switch terminals, Fig. 13. 3. Remove switch from steering column jacket. INSTALLATION 1. Place gear selector in Neutral position. 2. Align actuator on switch with hole in the shift tube, Fig. 13. 3. Position rearward side of switch (connector side) to fit into cutout in the lower shift bowl. 4. Push down on front of switch. Tangs on housing back will snap into place in rectangular holes in the shift bowl. 5. Connect switch electrical connector, then the battery ground cable. 6. Adjust switch by moving the gear selector to Park position. The main housing and housing back should ratchet, providing proper switch adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Recalls for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects Technical Service Bulletin # 94C16 Date: 940101 Campaign - Starter Motor Pinion Stop Collar Defects Number: 94C16 Section: 6A Date: Jan., 1994 Subject: PRODUCT CAMPAIGN 94C16 - STARTER MOTOR PINION STOP Model and Year: 1994 J, L, W CARS; G, U, M/L VANS; C/K, S/T TRUCKS Notice To: All Chevrolet/Geo Dealers THIS IS A SUMMARY OF CHEVROLET CAMPAIGN NUMBER 94C16, ORIGINALLY ISSUED AS DCS ADMINISTRATIVE MESSAGE 01-007 ON JANUARY 4, 1994. General Motors has determined that all 1994 Chevrolet vehicles listed in this campaign may have a starter motor with an improperly heat treated pinion stop collar. This condition may result in part failure causing slow engine crank speeds or an engine no start condition. To prevent the failure from occurring, dealers are to inspect and repair certain starter motors from the vehicles identified below. Starter motors with date codes of N093, N103, N113, N123, N153 and N163 are to be repaired by replacing the pinion stop collar and retaining ring. No repairs are necessary on motors that fall outside of these date codes. Vehicles Involved Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Recalls for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5318 Involved are all 1994 Chevrolet vehicles built within the VIN breakpoints: Involved vehicles have been identified by Vehicle Identification Number Computer Listings. Computer listings contain the complete Vehicle Identification Number, owner name and address data, and are furnished to involved dealers with the campaign bulletin. Owner name and address data furnished will enable dealers to follow-up with owners involved in this campaign. These listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned. Owner Notification Owners will be notified of this campaign on their vehicles by Chevrolet Motor Division (see copy of owner letter included with this bulletin). Dealer Campaign Responsibility All unsold new vehicles in dealers' possession and subject to this campaign must be held and inspected/repaired per the service procedure of this campaign bulletin before owners take possession of these vehicles. Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward. Owners of vehicles recently sold from your new vehicle inventory with no owner information indicated on the dealer listing, are to be contacted by the dealer, and arrangements made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such owners a copy of the owners letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the owner may not as yet have received the notification letter. In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Recalls for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5319 Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). To ensure these parts will be obtained as soon as possible, they should be ordered from GMSPO on a "C.I.O." order with no special instruction code, but on an advise code (2). NOTICE: All dealers were preshipped a quantity of each part during the week of January 3, 1994. Please do not order excessive quantities for stock as this causes material shortages and unnecessary customer inconvenience. Service Procedure STARTER MOTOR REMOVAL AND REPLACEMENT 1. All vehicles within breakpoints should be inspected to determine starter motor date codes. Date codes are imprinted on upper half of tag located on motor end of starter. Tag information is read upside down as viewed from bottom. 2. A.) Most vehicles may be inspected by utilizing a mirror, flashlight, and/or use of a pliable material such as modeling clay or similar material to make an impression of the date code. After making an impression, read code with a mirror. B.) Some vehicles such as W-Cars with L82 engines may require removal of an oil filter drip pan to gain access to read the date codes. C.) Some vehicles equipped with oil coolers and 2.0L (LE4) equipped J-Cars & T trucks will require starter motor removal to read date codes per section 6D2 of the service manual. 3. Remove all starter motor assembly per instructions in appropriate 1994 service manual section 6D2 with date codes N093, N103, N113, N123, N133, N153 & N163 and perform pinion stop collar procedure. Notice: Disconnect negative battery cable after noting radio station settings. 4. Reinstall starter motor per instructions in service manual, section 6D2. Reset radio settings as noted and reset clock. 5. Install Campaign Identification Label. PINION STOP COLLAR REPLACEMENT PROCEDURE 1. Remove field lead attaching screw from solenoid terminal. 2. Loosen but do not remove through bolts in starter motor assembly. Do not separate the commutator end and frame. 3. Separate frame with armature inside from housing. 4. Remove thrust collar from end of shaft if it is not stuck to housing. 5. Use care in removing and installing retaining ring to prevent scratching or damaging armature shaft. 6. Remove pinion stop retaining ring first by prying pinion stop collar off the ring. Pry pinion stop ring off armature with a small screw driver. Do not reuse ring. 7. Remove pinion stop collar from armature shaft. Do not reuse collar. 8. Install new pinion stop collar on armature shaft. Flat side goes towards pinion. 9. Install new retaining ring onto armature shaft and seat it in shaft groove. Use due care not to damage armature shaft. 10. Install thrust collar onto armature shaft with small flange toward retaining ring. Use two pliers to squeeze pinion stop collar and the thrust collar to seat the stop collar on the retaining ring. 11. Assemble frame, armature and drive assembly into housing. Ensure shift lever is engaged with drive assembly. Ensure armature shaft is engaged with housing bearing. Tighten through bolts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Recalls for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5320 12. Install starter field lead to solenoid. 13. Install Campaign Identification Label Campaign Identification Label and Claim Information Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label". Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen. Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner. Additional "Campaign Identification Labels" can be obtained from DAC. Apply "Campaign Identification Label" only on a clean, dry surface. CLAIM INFORMATION Submit a Product Campaign Claim with the information as indicated. Dealers will automatically receive the correct labor and material allowance based on the labor operation performed. Refer to the Chevrolet Claims Processing Manual for details on Product Campaign Claim submission. Owner Letter January, 1994 Dear Chevrolet Owner: This notice is sent to inform you that Chevrolet Motor Division is conducting a recall campaign that includes your vehicle. REASON FOR THIS RECALL General Motors has determined that certain 1994 Chevrolet vehicles, such as yours, may have a starter motor with an improperly heat treated pinion stop collar. This condition may result in part failure causing slow engine crank speeds or an engine no start condition. WHAT WE WILL DO Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Recalls for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5321 To prevent the failure from occurring, your dealer will inspect and, if necessary repair, the starter motor on your vehicle. This service will be performed for you at no charge. WHAT YOU SHOULD DO Please contact your Chevrolet dealer as soon as possible to arrange a service date and so the dealer may order the necessary parts for the repair. Instructions for performing this service have been sent to your dealer and parts are available. Please contact your dealer to arrange a service date as soon as possible. You may ask your dealer if you wish to know how much time will be needed to schedule and process your vehicle. The enclosed owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you have sold or traded your vehicle, please let us know by completing the postage paid reply card and returning it to us. We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects Technical Service Bulletin # 94C16 Date: 940101 Campaign - Starter Motor Pinion Stop Collar Defects Number: 94C16 Section: 6A Date: Jan., 1994 Subject: PRODUCT CAMPAIGN 94C16 - STARTER MOTOR PINION STOP Model and Year: 1994 J, L, W CARS; G, U, M/L VANS; C/K, S/T TRUCKS Notice To: All Chevrolet/Geo Dealers THIS IS A SUMMARY OF CHEVROLET CAMPAIGN NUMBER 94C16, ORIGINALLY ISSUED AS DCS ADMINISTRATIVE MESSAGE 01-007 ON JANUARY 4, 1994. General Motors has determined that all 1994 Chevrolet vehicles listed in this campaign may have a starter motor with an improperly heat treated pinion stop collar. This condition may result in part failure causing slow engine crank speeds or an engine no start condition. To prevent the failure from occurring, dealers are to inspect and repair certain starter motors from the vehicles identified below. Starter motors with date codes of N093, N103, N113, N123, N153 and N163 are to be repaired by replacing the pinion stop collar and retaining ring. No repairs are necessary on motors that fall outside of these date codes. Vehicles Involved Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5327 Involved are all 1994 Chevrolet vehicles built within the VIN breakpoints: Involved vehicles have been identified by Vehicle Identification Number Computer Listings. Computer listings contain the complete Vehicle Identification Number, owner name and address data, and are furnished to involved dealers with the campaign bulletin. Owner name and address data furnished will enable dealers to follow-up with owners involved in this campaign. These listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned. Owner Notification Owners will be notified of this campaign on their vehicles by Chevrolet Motor Division (see copy of owner letter included with this bulletin). Dealer Campaign Responsibility All unsold new vehicles in dealers' possession and subject to this campaign must be held and inspected/repaired per the service procedure of this campaign bulletin before owners take possession of these vehicles. Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward. Owners of vehicles recently sold from your new vehicle inventory with no owner information indicated on the dealer listing, are to be contacted by the dealer, and arrangements made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such owners a copy of the owners letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the owner may not as yet have received the notification letter. In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5328 Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). To ensure these parts will be obtained as soon as possible, they should be ordered from GMSPO on a "C.I.O." order with no special instruction code, but on an advise code (2). NOTICE: All dealers were preshipped a quantity of each part during the week of January 3, 1994. Please do not order excessive quantities for stock as this causes material shortages and unnecessary customer inconvenience. Service Procedure STARTER MOTOR REMOVAL AND REPLACEMENT 1. All vehicles within breakpoints should be inspected to determine starter motor date codes. Date codes are imprinted on upper half of tag located on motor end of starter. Tag information is read upside down as viewed from bottom. 2. A.) Most vehicles may be inspected by utilizing a mirror, flashlight, and/or use of a pliable material such as modeling clay or similar material to make an impression of the date code. After making an impression, read code with a mirror. B.) Some vehicles such as W-Cars with L82 engines may require removal of an oil filter drip pan to gain access to read the date codes. C.) Some vehicles equipped with oil coolers and 2.0L (LE4) equipped J-Cars & T trucks will require starter motor removal to read date codes per section 6D2 of the service manual. 3. Remove all starter motor assembly per instructions in appropriate 1994 service manual section 6D2 with date codes N093, N103, N113, N123, N133, N153 & N163 and perform pinion stop collar procedure. Notice: Disconnect negative battery cable after noting radio station settings. 4. Reinstall starter motor per instructions in service manual, section 6D2. Reset radio settings as noted and reset clock. 5. Install Campaign Identification Label. PINION STOP COLLAR REPLACEMENT PROCEDURE 1. Remove field lead attaching screw from solenoid terminal. 2. Loosen but do not remove through bolts in starter motor assembly. Do not separate the commutator end and frame. 3. Separate frame with armature inside from housing. 4. Remove thrust collar from end of shaft if it is not stuck to housing. 5. Use care in removing and installing retaining ring to prevent scratching or damaging armature shaft. 6. Remove pinion stop retaining ring first by prying pinion stop collar off the ring. Pry pinion stop ring off armature with a small screw driver. Do not reuse ring. 7. Remove pinion stop collar from armature shaft. Do not reuse collar. 8. Install new pinion stop collar on armature shaft. Flat side goes towards pinion. 9. Install new retaining ring onto armature shaft and seat it in shaft groove. Use due care not to damage armature shaft. 10. Install thrust collar onto armature shaft with small flange toward retaining ring. Use two pliers to squeeze pinion stop collar and the thrust collar to seat the stop collar on the retaining ring. 11. Assemble frame, armature and drive assembly into housing. Ensure shift lever is engaged with drive assembly. Ensure armature shaft is engaged with housing bearing. Tighten through bolts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5329 12. Install starter field lead to solenoid. 13. Install Campaign Identification Label Campaign Identification Label and Claim Information Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label". Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen. Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner. Additional "Campaign Identification Labels" can be obtained from DAC. Apply "Campaign Identification Label" only on a clean, dry surface. CLAIM INFORMATION Submit a Product Campaign Claim with the information as indicated. Dealers will automatically receive the correct labor and material allowance based on the labor operation performed. Refer to the Chevrolet Claims Processing Manual for details on Product Campaign Claim submission. Owner Letter January, 1994 Dear Chevrolet Owner: This notice is sent to inform you that Chevrolet Motor Division is conducting a recall campaign that includes your vehicle. REASON FOR THIS RECALL General Motors has determined that certain 1994 Chevrolet vehicles, such as yours, may have a starter motor with an improperly heat treated pinion stop collar. This condition may result in part failure causing slow engine crank speeds or an engine no start condition. WHAT WE WILL DO Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Starter Motor: > 94C16 > Jan > 94 > Campaign - Starter Motor Pinion Stop Collar Defects > Page 5330 To prevent the failure from occurring, your dealer will inspect and, if necessary repair, the starter motor on your vehicle. This service will be performed for you at no charge. WHAT YOU SHOULD DO Please contact your Chevrolet dealer as soon as possible to arrange a service date and so the dealer may order the necessary parts for the repair. Instructions for performing this service have been sent to your dealer and parts are available. Please contact your dealer to arrange a service date as soon as possible. You may ask your dealer if you wish to know how much time will be needed to schedule and process your vehicle. The enclosed owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you have sold or traded your vehicle, please let us know by completing the postage paid reply card and returning it to us. We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Page 5331 Starter Motor: Specifications Engine ................................................................................................................................................. .............................................................. 4.3L/V6-262 VIN ....................................................................................................................................................... ...................................................................... W & Z Starter ID No. ....................................................................................................................................... .................................................................. 10455050 Free Speed Test Amps ................................................................................................................................................... ...................................................................... 47-70 Volts ................................................................... ............................................................................................................................................................ 10 RPM................................................................................................................................................. ............................................................... 6500-11,000 Solenoid Hold-In Windings, Amps ...................................................................................................................... .................................................................... 10-20 Pull-In Windings, Amps ........................................ ................................................................................................................................................... 60-85 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Page 5332 Starter Motor: Locations Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Page 5333 Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Technical Service Bulletins > Page 5334 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions Starter Motor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5337 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5338 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5339 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5340 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5341 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5342 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5343 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5344 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5345 Starter Motor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5346 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5347 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5348 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5349 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5350 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5351 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5352 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5353 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5354 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5355 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5356 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5357 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5358 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5359 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5360 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5361 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5362 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5363 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5364 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5365 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5366 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Diagram Information and Instructions > Page 5367 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Diagrams > Page 5368 Starter Motor: Description and Operation Fig. 9 Exploded View Of Delco-Remy SD-260 Series Starter Motor. The Delco-Remy SD-260 starter motor has the solenoid shift lever mechanism and the solenoid plunger enclosed in the drive housing to protect them from exposure to road dirt, icing conditions and splash. They have an extruded field frame and an overrunning clutch type drive. The overrunning clutch is operated by a solenoid switch mounted to a flange on the drive housing. The solenoid is attached to the drive end housing by two screws. The cover can be removed to inspect the contacts and contact disc, but the switch is serviced as an assembly only. Most motors of this type have graphite and oil impregnated bronze bearings which ordinarily require no added lubrication except at time of overhaul when a few drops of light engine oil should be placed on each bearing before reassembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Testing and Inspection > Free Speed Inspection Starter Motor: Testing and Inspection Free Speed Inspection Fig. 12 Motor Free Speed Inspection. This test is performed during bench testing. With the circuit connected, use a tachometer to measure armature revolutions per minute. Failure of the motor to perform to specifications may be due to light or dry bearings, or high resistance connections. Starter motors do not require lubrication except during overhaul. At this time a couple drops of light oil may be applied to bearings. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Testing and Inspection > Free Speed Inspection > Page 5371 Starter Motor: Testing and Inspection Pinion Clearance Inspection Fig. 13 Pinion Clearance Inspection Connections. Fig. 14 Pinion Clearance Inspection. There is no provision for adjusting pinion clearance on this motor, but clearance should be checked after motor reassembly. When the shift lever is assembled properly, pinion clearance should be 0.010-0.060 inch.When clearance is not within specifications, it may indicate excessive wear of the solenoid linkage or the shift lever yoke buttons. Check pinion clearance as follows: 1. Disconnect motor field coil connector from solenoid motor terminal, then insulate end carefully. 2. Connect one battery lead to solenoid switch terminal, then the other lead to the solenoid frame. 3. Connect a jumper lead to solenoid motor terminal. Momentarily flash lead to solenoid frame. This will shift pinion into cranking position until the battery is disconnected. 4. Push pinion back toward commutator end as far as possible to take up any slack movement, then check clearance with a feeler gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Testing and Inspection > Page 5372 Starter Motor: Service and Repair STARTER MOTOR REPLACEMENT Remove or Disconnect - Place the vehicle on a hoist. 1. Negative battery cable. Starter Motor Mounting On The 2.5L Engine 2. Brush end mounting bracket on the 2.5L engine starter motor. 3. Solenoid wiring. On the 4.3L, raise the vehicle halfway on the hoist, and reach through the right wheel well. - Raise the vehicle. 4 Wheel Drive Vehicles: 4. Four bolts on the skid plate (if equipped). 5. Skid plate (if equipped). 8. Bolts and the two brackets holding the brake line to the crossmember. 7. Crossmember (three bolts on each side). 8. Bracket holding the transmission fluid cooler lines to the flywheel housing, brace rod to the flywheel housing and/or the lower flywheel housing if necessary. All Models: 9. Two bolts holding the starter to the engine. 10. Starter and the shim (if present). Install or Connect Meshing Starter And Flywheel Teeth Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Testing and Inspection > Page 5373 Flywheel To Pinion Clearence Shimming The Starter Motor On The 2.8L Engine Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Testing and Inspection > Page 5374 Shimming The Starter Motor On The 2.8L Engine 1. Starter and shim (if present) to the engine with bolts. Tighten - Bolts on the 2.5L engine to 43 N.m (31 ft. lbs.). - Bolts on the 2.8L and 4.3L engines to 45 N.m (33 ft. lbs.). 4 Wheel Drive Vehicles: 2. Lower flywheel housing (if removed). 3. Transmission lines bracket to the housing (if present). 4. Brace rod to the housing (if equipped). 5. Crossmember to the frame end with six bolts. 6. Two brake line brackets to the crossmember with bolts. 7. Skid plate (if equipped). 4.3L Engine: - Lower the hoist halfway. 8. Solenoid wiring by reaching through the right wheel well. All Vehicles: - Lower the vehicle. Starter Motor Mounting On The 2.5L Engine 9. Brush end mounting bracket and wiring (2.5L). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Motor > Component Information > Testing and Inspection > Page 5375 Tighten - Mounting bracket nuts to 8 N.m (75 in. lbs.). 10. Wires to the solenoid terminals. 11. Negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Locations Starter Solenoid: Locations Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Locations > Page 5379 Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions Starter Solenoid: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5382 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5383 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5384 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5385 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5386 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5387 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5388 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5389 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5390 Starter Solenoid: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5391 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5392 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5393 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5394 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5395 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5396 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5397 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5398 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5399 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5400 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5401 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5402 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5403 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5404 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5405 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5406 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5407 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5408 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5409 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5410 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5411 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Starting System > Starter Solenoid > Component Information > Diagrams > Diagram Information and Instructions > Page 5412 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Circuit Breaker > Component Information > Specifications Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Circuit Breaker > Component Information > Specifications > Page 5417 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 Diode: Locations D100 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5422 Diode: Locations D101 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5423 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5424 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5425 Diode: Locations D102 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5426 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5427 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5428 Diode: Locations D104 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5429 Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 5438 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 5448 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > Page 5454 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Locations > In-Line Fuse Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Locations > In-Line Fuse > Page 5457 Outside Rear View Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Locations > In-Line Fuse > Page 5458 Steering Column Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse > Component Information > Locations > Page 5459 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics Fuse Block: Technical Service Bulletins Shift Interlock/Fuse Block - Revised Schematics File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-81-26 Date: January, 1997 SERVICE MANUAL UPDATE Subject: Section 8A - Electrical Diagnosis - Revised Schematics Models: 1994 Chevrolet and GMC M/L Models Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics > Page 5464 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics > Page 5465 This bulletin revises the schematics on Pages 8A-11-8 and 8A-138-2 in the 1994 M/L Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel Fuse Block: Locations Fuse Panel Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5468 Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5469 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5470 Fuse Block: Locations Fuse Block View Fuse Block Details: Front View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5471 Fuse Block Details: Rear View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5474 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5475 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5476 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5477 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5478 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5479 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5480 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5481 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5482 Fuse Block: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5483 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5484 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5485 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5486 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5487 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5488 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5489 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5490 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5491 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5492 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5493 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5494 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5495 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5496 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5497 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5498 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5499 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5500 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5501 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5502 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5503 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5504 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5505 Fuse Block: Connector Views C109, Engine To Fuse Block C110, Engine To Fuse Block In-Line Fuse Block Tap C283, Fuse Block Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5506 C293, Fuse Block Tap C258, Fuse Block Tap C257, Fuse Block Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5507 C269, Fuse Block Tap C109, Fuse Block To Engine C110, Fuse Block To Engine In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5508 Fuse Block: Electrical Diagrams Convenience Center Details (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5509 Convenience Center Details (Part 2 Of 2) Wiring Diagram Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5510 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5511 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5512 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5513 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5514 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5515 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5516 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5517 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Application and ID > Front View Fuse Block Details: Front View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fuse Block > Component Information > Application and ID > Front View > Page 5520 Fuse Block Details: Rear View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Fusible Link > Component Information > Locations Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair Grounding Point: Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5528 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5529 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5530 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5531 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5532 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5533 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block Multiple Junction Connector: Locations Battery Junction Block Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5538 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5539 Multiple Junction Connector: Locations Battery Junction Block Lead Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5540 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5541 Multiple Junction Connector: Locations Bus Bar Ground Courtesy Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5542 Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5543 I/P Wiring, LH Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Diagrams > Bus Bar Ground Tap C259, Bus Bar Ground Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Multiple Junction Connector > Component Information > Diagrams > Bus Bar Ground Tap > Page 5546 C198, Battery To Junction Block Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Specifications Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center Relay Box: Locations Convenience Center Fuse Block And Convenience Center Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5553 Crossbody Harness The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5554 Relay Box: Locations Relay Center The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap C283, Convenience Center Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5557 C206, Convenience Center To I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5558 C206, Convenience Center To I/P Cluster In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5559 C206, I/P Cluster To Convenience Center In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5560 C206, I/P To Convenience Center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Page 5561 Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Specifications Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center Relay Box: Locations Convenience Center Fuse Block And Convenience Center Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5567 Crossbody Harness The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5568 Relay Box: Locations Relay Center The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap C283, Convenience Center Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5571 C206, Convenience Center To I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5572 C206, Convenience Center To I/P Cluster In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5573 C206, I/P Cluster To Convenience Center In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5574 C206, I/P To Convenience Center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Page 5575 Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5584 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5585 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5586 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5592 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5593 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5594 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5599 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5600 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5601 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5602 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5603 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5604 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair > Page 5609 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5615 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5616 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5617 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5618 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5619 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5620 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Starting and Charging > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair > Page 5625 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Circuit Breaker > Component Information > Specifications Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Circuit Breaker > Component Information > Specifications > Page 5630 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 Diode: Locations D100 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5635 Diode: Locations D101 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5636 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5637 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5638 Diode: Locations D102 Engine Compartment Wiring, LH Side Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5639 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5640 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5641 Diode: Locations D104 Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Diode > Component Information > Locations > D100 > Page 5642 Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 5651 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 5661 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Technical Service Bulletins > Page 5667 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Locations > In-Line Fuse Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Locations > In-Line Fuse > Page 5670 Outside Rear View Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Locations > In-Line Fuse > Page 5671 Steering Column Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse > Component Information > Locations > Page 5672 Fuse And Circuit Breaker Identification Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics Fuse Block: Technical Service Bulletins Shift Interlock/Fuse Block - Revised Schematics File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-81-26 Date: January, 1997 SERVICE MANUAL UPDATE Subject: Section 8A - Electrical Diagnosis - Revised Schematics Models: 1994 Chevrolet and GMC M/L Models Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics > Page 5677 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Technical Service Bulletins > Shift Interlock/Fuse Block - Revised Schematics > Page 5678 This bulletin revises the schematics on Pages 8A-11-8 and 8A-138-2 in the 1994 M/L Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel Fuse Block: Locations Fuse Panel Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5681 Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5682 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5683 Fuse Block: Locations Fuse Block View Fuse Block Details: Front View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Locations > Fuse Panel > Page 5684 Fuse Block Details: Rear View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5687 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5688 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5689 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5690 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5691 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5692 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5693 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5694 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5695 Fuse Block: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5696 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5697 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5698 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5699 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5700 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5701 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5702 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5703 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5704 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5705 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5706 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5707 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5708 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5709 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5710 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5711 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5712 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5713 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5714 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5715 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5716 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5717 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5718 Fuse Block: Connector Views C109, Engine To Fuse Block C110, Engine To Fuse Block In-Line Fuse Block Tap C283, Fuse Block Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5719 C293, Fuse Block Tap C258, Fuse Block Tap C257, Fuse Block Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5720 C269, Fuse Block Tap C109, Fuse Block To Engine C110, Fuse Block To Engine In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5721 Fuse Block: Electrical Diagrams Convenience Center Details (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5722 Convenience Center Details (Part 2 Of 2) Wiring Diagram Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5723 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5724 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5725 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5726 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5727 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5728 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5729 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 5730 Fuse Block Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Application and ID > Front View Fuse Block Details: Front View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fuse Block > Component Information > Application and ID > Front View > Page 5733 Fuse Block Details: Rear View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Fusible Link > Component Information > Locations Generator And Starter Wiring - 4.3L Engine (Vin Z), Other Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair Grounding Point: Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5741 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5742 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5743 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5744 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5745 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Grounding Point > Component Information > Technical Service Bulletins > Electrical - Information For Electrical Ground Repair > Page 5746 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block Multiple Junction Connector: Locations Battery Junction Block Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5751 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5752 Multiple Junction Connector: Locations Battery Junction Block Lead Engine Wiring, Battery, And Leads Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5753 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5754 Multiple Junction Connector: Locations Bus Bar Ground Courtesy Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5755 Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Locations > Battery Junction Block > Page 5756 I/P Wiring, LH Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Diagrams > Bus Bar Ground Tap C259, Bus Bar Ground Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Multiple Junction Connector > Component Information > Diagrams > Bus Bar Ground Tap > Page 5759 C198, Battery To Junction Block Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Specifications Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center Relay Box: Locations Convenience Center Fuse Block And Convenience Center Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5766 Crossbody Harness The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5767 Relay Box: Locations Relay Center The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap C283, Convenience Center Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5770 C206, Convenience Center To I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5771 C206, Convenience Center To I/P Cluster In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5772 C206, I/P Cluster To Convenience Center In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5773 C206, I/P To Convenience Center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Page 5774 Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Specifications Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center Relay Box: Locations Convenience Center Fuse Block And Convenience Center Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5780 Crossbody Harness The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Locations > Convenience Center > Page 5781 Relay Box: Locations Relay Center The fuse/relay convenience center is located behind the left hand side of the instrument panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap C283, Convenience Center Tap Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5784 C206, Convenience Center To I/P Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5785 C206, Convenience Center To I/P Cluster In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5786 C206, I/P Cluster To Convenience Center In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Convenience Center Tap > Page 5787 C206, I/P To Convenience Center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Relay Box > Component Information > Diagrams > Page 5788 Relay Data Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5797 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5798 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > Customer Interest: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5799 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5805 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5806 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 5807 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5812 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5813 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5814 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5815 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5816 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5817 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair > Page 5822 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5828 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5829 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5830 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5831 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5832 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 10-08-45-001B > Oct > 10 > Electrical - Information For Electrical Ground Repair > Page 5833 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Power and Ground Distribution > Wiring Harness > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wiring Harness: > 06-08-45-004 > May > 06 > Electrical - Instrument Panel & General Wiring Repair > Page 5838 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications Alignment: Technical Service Bulletins Steering/Suspension - Wheel Alignment Specifications WARRANTY ADMINISTRATION Bulletin No.: 05-03-07-009C Date: December 09, 2010 Subject: Wheel Alignment Specifications, Requirements and Recommendations for GM Vehicles Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks Supercede: This bulletin is being extensively revised to provide technicians and warranty administrators with an all inclusive guide for wheel alignments. PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. Please discard Corporate Bulletin Number 05-03-07-009B (Section 03 - Suspension). Purpose The purpose of this bulletin is to provide retail, wholesale and fleet personnel with General Motors' warranty service requirements and recommendations for customer concerns related to wheel alignment. For your convenience, this bulletin updates and centralizes all of GM's Standard Wheel Alignment Service Procedures, Policy Guidelines and bulletins on wheel alignment warranty service. Important PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. The following five (5) key steps are a summary of this bulletin and are REQUIRED in completing a successful wheel alignment service. 1. Verify the vehicle is in an Original Equipment condition for curb weight, tires, wheels, suspension and steering configurations. Vehicles modified in any of these areas are not covered for wheel alignment warranty. 2. Review the customer concern relative to "Normal Operation" definitions. 3. Verify that vehicle is within the "Mileage Policy" range. 4. Document wheel alignment warranty claims appropriately for labor operations E2000 and E2020. The following information must be documented or attached to the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 5. Use the proper wheel alignment equipment (preferred with print-out capability), process and the appropriate calibration maintenance schedules. Important If it is determined that a wheel alignment is necessary under warranty, use the proper labor code for the repair. E2000 for Steering Wheel Angle and/or Front Toe set or E2020 for Wheel Alignment Check/Adjust includes Caster, Camber and Toe set (Wheel alignment labor time for other component repairs is to be charged to the component that causes a wheel alignment operation.). The following flowchart is to help summarize the information detailed in this bulletin and should be used whenever a wheel alignment is performed. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5844 Verify Original Equipment Condition of the Vehicle - Verify that Original Equipment Tires and Wheels or Official GM Accessory Tires and Wheels are on the vehicle. - Verify that aftermarket suspension "Lift" or "Lowering" Kits or other suspension alterations have NOT been done to the vehicle. - Check for accidental damage to the vehicle; for example, severe pothole or curb impacts, collision damage that may have affected the wheel alignment of the vehicle; e.g., engine cradles, suspension control arms, axles, wheels, wheel covers, tires may show evidence of damage/impact. - Check to be sure vehicle has seen "Normal Use" rather than abuse; e.g., very aggressive driving may show up by looking at the tires and condition of the vehicle. - Check for other additional equipment items that may significantly affect vehicle mass such as large tool boxes, campers, snow plow packages (without the snowplow RPO), etc., especially in trucks and cutaway/incomplete vehicles. Significant additional mass can affect trim height and wheel alignment of the vehicle and may necessitate a customer pay wheel alignment when placed semi-permanently in the vehicle (Upfitter instructions are to realign the vehicle after placement of these types of items. (This typically applies to trucks and incomplete vehicles that can be upfit with equipment such as the above.) Customer Concerns, "Normal Operation" Conditions and "Mileage Policy" Possible Concerns The following are typical conditions that may require wheel alignment warranty service: 1. Lead/Pull: defined as "at a constant highway speed on a typical straight road, the amount of effort required at the steering wheel to maintain the vehicle's straight heading." Important Please evaluate for the condition with hands-on the steering wheel. Follow the "Vehicle Leads/Pulls" diagnostic tree located in SI to determine the cause of a lead/pull concern. Lead/Pull concerns can be due to road crown or road slope, tires, wheel alignment or even in rare circumstances a steering gear issue. Lead/pull concerns due to road crown are considered "Normal Operation" and are NOT a warrantable condition -- the customer should be advised that this is "Normal Operation." Important Some customers may comment on a "Lead/Pull" when they hold the steering wheel in a level condition. If so, this is more likely a "steering wheel angle" concern because the customer is "steering" the vehicle to obtain a "level" steering wheel. 2. Steering wheel angle to the left or right (counter-clockwise or clockwise, respectively): Defined as the steering wheel angle (clocking) deviation from "level" while maintaining a straight heading on a typical straight road. 3. Irregular or Premature tire wear: Slight to very slight "feathering" or "edge" wear on the shoulders of tires is NOT considered unusual and should even out with a tire rotation; if the customer is concerned about a "feathering" condition of the tires, the customer could be advised to rotate the tires earlier than the next scheduled mileage/maintenance interval (but no later than the next interval). Be sure to understand the customer's driving habits as this will also heavily influence the tire wear performance; tire wear from aggressive or abusive driving habits is NOT a warrantable condition. Important Slight or mild feathering, cupping, edge or heel/toe wear of tire tread shoulders is "normal" and can show up very early in a tire/vehicle service mileage; in fact, some new tires can show evidence of feathering from the factory. These issues do NOT affect the overall performance and tread life of the tire. Dealer personnel should always check the customer's maintenance records to ensure that tire inflation pressure is being maintained to placard and that the tires are being rotated (modified-X pattern) at the proper mileage intervals. Wheel alignments are NOT to be performed for the types of "Normal" Tire Feathering shown in Figures 1-4 below. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5845 Figure 1: Full Tread View - "NORMAL" Tire "Feathering" Wear on the Shoulder/Adjacent/Center Ribs Figure 2: Tire Shoulder View Example 1 - "NORMAL" Tire "Feathering" Wear on the Shoulder Figure 3: Tire Shoulder View Example 2 - "NORMAL" Tire "Feathering" Wear Figure 4: Detail Side View of Tire Shoulder Area - "NORMAL" Tire "Feathering" Wear Important When a wheel alignment is deemed necessary for tire wear, be sure to document on the repair order, in as much detail as possible, the severity and type of tire wear (e.g., severe center wear or severe inside or outside shoulder wear) and the position of the tire on the vehicle (RF, LF, LR, RR). Please note the customer's concern with the wear such as, noise, appearance, wear life, etc. A field product report with pictures of the tire wear condition is recommended. Refer to Corporate Bulletin Number 02-00-89-002J and #07-00-89-036C. 4. Other repairs that affect wheel alignment; e.g., certain component replacement such as suspension control arm replacement, engine cradle adjustment/replace, steering gear replacement, steering tie rod replace, suspension strut/shock, steering knuckle, etc. may require a wheel alignment. Important If other components or repairs are identified as affecting the wheel alignment, policy calls for the wheel alignment labor time to be charged to the replaced/repaired component's labor operation time rather than the wheel alignment labor operations. Important Vibration type customer concerns are generally NOT due to wheel alignment except in the rare cases; e.g., extreme diagonal wear across the tread. In general, wheel alignments are NOT to be performed as an investigation/correction for vibration concerns. "Normal Operation" Conditions Vehicle Lead/Pull Due to Road Crown or Slope: As part of "Normal Operation," vehicles will follow side-to-side or left to right road crown or slope. Be sure to verify from the customer the types of roads they are driving as they may not recognize the influence of road crown on vehicle lead/pull and steering wheel angle. If a vehicle requires significant steering effort to prevent it from "climbing" the road crown there may be an issue to be looked into further. Important Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5846 A wheel alignment will generally NOT correct vehicles that follow the road crown since this is within "Normal Operation." Mileage Policy The following mileage policy applies for E2020 and E2000 labor operations: Note Wheel Alignment is NOT covered under the New Vehicle Limited Warranty for Express and Savana Cutaway vehicles as these vehicles require Upfitters to set the wheel alignment after completing the vehicles. - 0-800 km (0-500 mi): E2000/E2020 claims ONLY allowed with Call Center Authorization. Due to the tie down during shipping, the vehicle's suspension requires some time to reach normal operating position. For this reason, new vehicles are generally NOT to be aligned until they have accumulated at least 800 km (500 mi). A field product report should accompany any claim within this mileage range. - 801-12,000 km (501-7,500 mi): - If a vehicle came from the factory with incorrect alignment settings, any resulting off-angle steering wheel, lead/pull characteristics or the rare occurrence of excessive tire wear would be apparent early in the life of the vehicle. The following policy applies: - Vehicles 100% Factory Set/Measured for Caster/Camber/Toe - Escalade/ESV/EXT, Tahoe/Suburban, Yukon/XL/Denali, Silverado/Sierra, Express/Savana, Corvette and Colorado/Canyon: E2000/E2020 Claims: Call Center Authorization Required - All Vehicles NOT 100% Factory Set/Measured for Caster/Camber/Toe as noted above: E2000/E2020 Claims: Dealer Service Manager Authorization Required - 12,001 km and beyond (7,501 miles and beyond): During this period, customers are responsible for the wheel alignment expense or dealers may provide on a case-by case basis a one-time customer enthusiasm claim up to 16,000 km (10,000 mi). In the event that a defective component required the use of the subject labor operations, the identified defective component labor operation will include the appropriate labor time for a wheel alignment as an add condition to the component repair. Important Only one wheel alignment labor operation claim (E2000 or E2020) may be used per VIN. Warranty Documentation Requirements When a wheel alignment service has been deemed necessary, the following items will need to be clearly documented on/with the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 1. Document the customer concern in as much detail as possible on the repair order and in the warranty administration system. Preferred examples: - Steering wheel is off angle in the counterclockwise direction by approximately x degrees or clocking position. - Vehicle lead/pulls to the right at approximately x-y mph. Vehicle will climb the road crown. Severe, Moderate or Slight. - RF and LF tires are wearing on the outside shoulders with severe feathering. Important In the event of a lead/pull or steering wheel angle concern, please note the direction of lead/pull (left or right) or direction of steering wheel angle (clockwise or counterclockwise) on the repair order and within the warranty claim verbatim. Important In the event of a tire wear concern, please note the position on the vehicle and where the wear is occurring on the tire; i.e., the RF tire is wearing on the inside shoulder. 2. Document the technician's findings on cause and correction of the issue. Examples: - Reset LF toe from 0.45 degrees to 0.10 degrees and RF toe from -0.25 degrees to 0.10 degrees to correct the steering wheel angle from 5 degrees counterclockwise to 0 degrees. - Reset LF camber from 0.25 degrees to -0.05 degrees to correct the cross-camber condition of +0.30 degrees to 0.00 degrees on the vehicle. - Front Sum toe was found to be 0.50 degrees, reset to 0.20 degrees. 3. Print-out the "Before" and "After" wheel alignment measurements/settings and attach them to the Repair Order or if print-out capability is not Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5847 available, measurements may also be clearly and legibly handwritten into the Wheel Alignment Repair Order Questionnaire attached to this bulletin. 4. Attach the Wheel Alignment Repair Order Questionnaire below along with the print-out of "Before" and "After" wheel alignment measurements to the Repair Order and retain for use by GM. Wheel Alignment Equipment and Process Wheel alignments must be performed with a quality machine that will give accurate results when performing checks. "External Reference" (image-based camera technology) is preferred. Please refer to Corporate Bulletin Number 05-00-89-029B: General Motors Dealership Critical Equipment Requirements and Recommendations. Requirements: - Computerized four wheel alignment system. - Computer capable of printing before and after alignment reports. - Computer capable of time and date stamp printout. - Racking system must have jacking capability - Racking system must be capable of level to 1.6 mm (1/16 in) - Appropriate wheel stops and safety certification - Built-in turn plates and slip plates - Wheel clamps capable of attaching to 20" or larger wheels - Racking capable of accepting any GM passenger car or light duty truck - Operator properly trained and ASE-certified (U.S. only) in wheel alignment Recommendations: Racking should have front and rear jacking capability. Equipment Maintenance and Calibration: Alignment machines must be regularly calibrated in order to give correct information. Most manufacturers recommend the following: - Alignment machines with "internal reference" sensors should be checked (and calibrated, if necessary) every six months. - Alignment machines with "external reference" (image-based camera technology) should be checked (and calibrated, if necessary) once a year. - Racks must be kept level to within 1.6 mm (1/16 in). - If any instrument that is part of the alignment machine is dropped or damaged in some way, check the calibration immediately. Check with the manufacturer of your specific equipment for their recommended service/calibration schedule. Wheel Alignment Process When performing wheel alignment measurement and/or adjustment, the following steps should be taken: Preliminary Steps: 1. Verify that the vehicle has a full tank of fuel (compensate as necessary). 2. Inspect the wheels and the tires for damage. 3. Inspect the tires for the proper inflation and irregular tire wear. 4. Inspect the wheel bearings for excessive play. 5. Inspect all suspension and steering parts for looseness, wear, or damage. 6. Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components. 7. Inspect the vehicle trim height. 8. Compensate for frame angle on targeted vehicles (refer to Wheel Alignment Specifications in SI). Satisfactory vehicle operation may occur over a wide range of alignment angles. However, if the wheel alignment angles are not within the range of specifications, adjust the wheel alignment to the specifications. Refer to Wheel Alignment Specifications in SI. Give consideration to excess loads, such as tool boxes, sample cases, etc. Follow the wheel alignment equipment manufacturer's instructions. Measure/Adjust: Important Prior to making any adjustments to wheel alignment on a vehicle, technicians must verify that the wheel alignment specifications loaded into their wheel alignment machine are up-to-date by comparing these to the wheel alignment specifications for the appropriate model and model year in SI. Using incorrect and/or outdated specifications may result in unnecessary adjustments, irregular and/or premature tire wear and repeat customer concerns Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5848 Important When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front wheel alignment angles. Perform the following steps in order to measure the front and rear alignment angles: 1. Install the alignment equipment according to the manufacturer's instructions. 2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment. 3. Measure the alignment angles and record the readings. If necessary, adjust the wheel alignment to vehicle specification and record the before and after measurements. Refer to Wheel Alignment Specifications in SI. Important Technicians must refer to SI for the correct wheel alignment specifications. SI is the only source of GM wheel alignment specifications that is kept up-to-date throughout the year. Test drive vehicle to ensure proper repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5849 Frame Angle Measurement (Express / Savana Only) ........ Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Technical Service Bulletins > Steering/Suspension - Wheel Alignment Specifications > Page 5850 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Specifications > Vehicle Ride (Trim) Height Specifications Alignment: Specifications Vehicle Ride (Trim) Height Specifications Fig. 5 Vehicle Ride Height Refer to Fig. 5 for vehicle ride height measurements and specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Specifications > Vehicle Ride (Trim) Height Specifications > Page 5853 Alignment: Specifications Alignment Specifications Front Alignment Specifications Caster Angle, Degrees Limits [01] ............................................................................................................................................ ..................................................... +1.70 to +3.70 Desired [02] ........................................................... ...................................................................................................................................... +2.20 to 3.20 Camber Angle, Degrees ...................................................................................................................... ................................................................................. Limits Left [01] ................................................................................................................................................ ....................................................... 0 to +1.60 Right [01] .................................................................... ................................................................................................................................. 0 to +1.60 Desired Left [02] ................................................................................................................................................ .......................................... +.30 to +1.30 [02] Right [02] ..................................................................... ................................................................................................................... +.30 to +1.30 [02] Toe-In, Degrees [03] ............................................................................................................................ ............................................................. +.05 to +.15 Ball Joint Wear .................................................................................................................................... ......................................................................... [04] [01] Left and right side to be equal within 1.0 deg.. [02] Left and right side to be equal within 0.5 deg.. [03] Left & right toe-in is set separately at each wheel w/ steering wheel held in straight ahead position. [04] Refer to /Steering & Suspension/ Suspension/ Ball Joint/ Testing & Inspection. Rear Alignment Specifications Camber Angle, Degrees [01] Limits ................................................................................................................................................... .................................................................. -3 to +5 Desired ................................................................ ............................................................................................................................................................ 1 Toe Out, Degrees [01] ......................................................................................................................... ..................................................................... 0 to .05 [01] Camber & toe are not adjustable Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Service and Repair > Preliminary Inspection Alignment: Service and Repair Preliminary Inspection Inspect the following components, adjust, repair or replace as required prior to performing front wheel alignment. 1. Inflate tires to cold specifications. 2. Ensure front tires are of same size, ply rating and load rating. 3. Inspect for excessive wheel bearing endplay. 4. Inspect for worn or damaged spindle ball joints. 5. Inspect steering gear mounting bolts for proper torque. 6. Inspect radius arm for bent or damaged condition. 7. Inspect radius arm to frame bushings for looseness or wear. 8. Inspect for loose or broken shackles. 9. Inspect for distorted or split jounce bumper. 10. Inspect suspension components for wear or damage. 11. Inspect vehicle ride height. Refer to, Specifications/ Mechanical/ Vehicle Ride Height. 12. Ensure vehicle is on level surface when performing alignment procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Service and Repair > Preliminary Inspection > Page 5856 Alignment: Service and Repair Front Caster and Camber Adjustment Fig. 1 Caster & Camber Adjustment. CASTER & CAMBER Before checking and adjusting caster and camber angles, jounce front bumper at least three times, to allow vehicle to return to normal "trim height". This will prevent false readings. Caster and camber adjustments are made by adding, subtracting or transfer of shims inserted between upper control arm shaft and frame bracket, Fig. 1. To adjust caster and/or camber, loosen upper control arm shaft-to-frame nuts, then add or subtract shims as necessary to adjust, then tighten nuts to specifications. After adjustment, the shim pack should have at least two threads of bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 0.40 inch. When adjusting caster, transfer shims from front to rear or rear to front. The transfer of one shim from rear to front bolt will decrease positive caster. When adjusting camber, change shims equally at both front and rear of shaft. Adding an equal number of shims at front and rear will decrease positive camber. When performing either caster or camber adjustment, always tighten nut on thinner shim pack first to improve shaft-to-frame clamping force and torque retention. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Alignment > System Information > Service and Repair > Preliminary Inspection > Page 5857 Alignment: Service and Repair Front Toe Adjustment Fig. 3 Tie Rod Adjuster Tube Fig. 4 Clamp & Sleeve Orientation TOE-IN To adjust toe-in, loosen clamp bolts at each end of steering tie rod adjusting sleeves. Replace the clamp bolts if the clamp bolt breakaway exceeds 80 inch lbs. With steering wheel in straight ahead position, turn tie rod adjusting sleeves to obtain proper adjustment. Decrease the length of the tie rod to increase toe-in. Increase the length of the tie rod to decrease the toe-in. After adjustment, check that number of threads showing on the inside of the adjusting sleeves are equal to within three and that the tie rod end stud lines up with steering knuckle. Position tie rod clamps and sleeves as shown in Figs. 3 and 4. Centerline of clamp bolt must be within 30 degrees of horizontal centerline. Torque nuts to 18 ft. lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Front Steering Knuckle > Component Information > Service and Repair Front Steering Knuckle: Service and Repair Fig. 17 Steering Knuckle Replacement 1. Raise front of vehicle and support with jack stands under front lift points, then remove wheel and tire assembly. Do not support vehicle under lower control arm at this time, as vehicle may slip off stands during knuckle removal. Spring tension will also aid in breaking ball joint studs loose from steering knuckle. 2. Remove brake caliper, then the brake and hub assembly. 3. Remove splash shield-to-steering knuckle attaching bolts. 4. Remove tie rod end from steering knuckle using tie rod end puller tool No. J-6627, or equivalent. 5. If steering knuckle is to be repaired or replaced, remove knuckle seal. 6. Remove ball joint studs from steering knuckle using ball joint remover tool No. J-23742, or equivalent. 7. Position a suitable jack under lower control arm near spring seat, then raise jack until it just supports control arm. Jack must remain in position under control arm during removal and installation to hold spring and control arm in position. 8. Raise upper control arm to disengage upper ball joint stud from knuckle. 9. Remove steering knuckle from lower ball joint stud, Fig. 17. 10. After removal, inspect and clean tapered hole in steering knuckle. If hole is out of round or damaged in any way, then knuckle must be replaced. 11. Reverse procedure to install. Tighten upper ball joint nut, lower ball joint nut, splash shield attaching bolts and tie rod end to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Bleeding > System Information > Service and Repair Power Steering Bleeding: Service and Repair Fig. 2 Power Steering System Bleed Chart 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine OFF. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Bleeding > System Information > Service and Repair > Page 5866 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. For additional bleed procedures, refer to Fig. 2. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold Power Steering Fluid: Customer Interest P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 5875 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 5876 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 5877 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold Power Steering Fluid: All Technical Service Bulletins P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 5883 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 5884 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Power Steering Fluid: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 5885 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Technical Service Bulletins > Steering - System Bleed Procedures Power Steering Pump: Technical Service Bulletins Steering - System Bleed Procedures Group Ref.: Steering/Suspension Bulletin No.: 383001 Date: December, 1993 INFORMATION SUBJECT: ILLUSTRATED STEERING SYSTEM BLEED PROCEDURE MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS THIS BULLETIN IS BEING REVISED TO ADD THE 1994 MODEL YEAR AND CHANGE THE ARTWORK. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: BUICK 93-3-5 3/02/93 CADILLAC T-93-76 5/12/93 CHEVROLET 93-146-3B 3/29/93 GM OF CANADA 93-3-102 5/05/93 OLDSMOBILE 2-93-59 (S.G.) 5/14/93 The steering system in 1994 and prior model year cars and light duty trucks should be bled after any of the following: - A power steering component is replaced. - A fluid line is disconnected. - A customer comments on steering system noise. Bleeding air from the steering system should be done in order to prevent pump damage, ensure proper operation, and to eliminate steering system noise. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Technical Service Bulletins > Steering - System Bleed Procedures > Page 5890 The illustration presents a pictorial illustration of the bleed procedure. This new procedure replaces previous steering system bleed procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Technical Service Bulletins > Steering - System Bleed Procedures > Page 5891 SERVICE PARTS INFORMATION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Specifications > Mechanical Specifications Power Steering Pump: Mechanical Specifications Component .......................................................................................................................................... ..................................................................... Ft. Lbs. Adjuster Jam Nut ................................................................................................................................. ............................................................................... 37 Adjuster Plug .................................................. .............................................................................................................................................................. ...... 20 Gear To Frame Bolts ............................................................................................................... ........................................................................................... 55 Intermediate Shaft Yoke Bolt .............. .............................................................................................................................................................. ................. 29 Power Steering Cooler Bracket .................................................................................... ...................................................................................................... 18 Power Steering Hose Clamp [01] ....................................................................................................................................................... ................................ 18 Power Steering Hose To Steering Gear Adapter Pipe ........................................................................................................................................................ 21 Power Steering Pressure Hose Flare Nut ........................................................................................... ................................................................................. 18 Pump Mounting Bolts ................................... .............................................................................................................................................................. ....... 37 Remote Reservoir Mounting Bolts [01] ................................................................................... .......................................................................................... 35 Reservoir To Steering Pump Housing Clamps [01] ........................................................................................................................................................... 35 [01] Inch lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Specifications > Mechanical Specifications > Page 5894 Power Steering Pump: Pressure, Vacuum and Temperature Specifications Relief Valve Settings, psi Minimum .............................................................................................................................................. ...................................................................... 1250 Maximum ............................................................. ...................................................................................................................................................... 1350 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Specifications > Page 5895 Power Steering Pump: Application and ID This vehicle uses a Vane type power steering pump w/ integral reservoir. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Specifications > Page 5896 Power Steering Pump: Description and Operation Fig. 2 Exploded view of power steering pump The hydraulic pump is a submerged, vane-type design. Submerged pumps have a housing and internal parts inside the reservoir and operate submerged in fluid. There are two openings at the rear of the pump housing. The larger opening contains the cam ring, pressure plate, thrust plate, rotor and vane assembly and the end plate. The smaller opening contains the pressure line union, flow control valve, and spring. The flow control orifice is part of the pressure line union. The pressure relief valve, located inside the flow control valve, limits pump pressure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Testing and Inspection > Power Steering System Test Power Steering Pump: Testing and Inspection Power Steering System Test NOTE: All tests are made with engine idling at normal operating temperature. Check idle speed adjustment and, if necessary, adjust to correct specification. 1. Place a container under steering gear or pump. 2. With engine Off, disconnect pressure hose at steering gear or power steering pump, then install J-5176-D to both hoses using adapter fitting No. J-5176-20 or equivalent. Gauge must be installed between shutoff valve and pump. 3. Open shutoff valve. 4. Remove filler cap from pump reservoir and check fluid level. Fill pump reservoir with power steering fluid to full mark on dipstick. Start engine and, momentarily holding steering wheel against stop, check connections for leakage. CAUTION: Do not hold wheel against stop for more than five seconds as pump can be damaged internally. 5. Bleed power steering system. 6. Insert thermometer No. J-5421-02 or equivalent in reservoir filler opening. Move steering wheel from stop to stop several times until thermometer indicates that hydraulic fluid in reservoir has reached a temperature of 150-170 °F. CAUTION: To prevent flat spotting tires, do not turn steering wheel more than five times without rolling vehicle to change tire to floor contact area. 7. Check pump fluid level. Add fluid if required. 8. When engine is at normal operating temperature, the initial pressure on gauge (valve open) should be within 80-125 psi. If pressure is in excess of 200 psi., check hoses for restrictions and poppet valve for proper assembly. 9. Open and close gauge valve fully three times. CAUTION: Do not leave valve closed for more than five seconds as pump could be damaged internally. 10. Record highest pressures attained each time. a. If pressures recorded are within specifications, and range of readings is within 50 psi., pump is functioning within specification. b. If pressures recorded are constant but more than 100 psi., below minimum specification, replace flow control valve and recheck. If pressures are still low, replace rotating group in pump. c. If pressure recorded are high, but do not repeat within 50 psi., flow control valve is sticking. Remove and clean valve. Remove any burrs using crocus cloth or fine hone. If system contains some dirt, flush system. If it is exceptionally dirty, both pump and gear must be completely disassembled, cleaned, flushed and reassembled before further use. 11. If pump checks within specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with maximum pump pressure recorded. If maximum pressure cannot be reached in either (or one) side of gear, gear is leaking internally and must be disassembled and repaired. 12. Turn engine Off, remove testing gauge, reconnect pressure hose, check fluid level and/or make needed repairs. 13. If problem still exists, steering and from suspension must be thoroughly examined. Refer to Troubleshooting. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Testing and Inspection > Power Steering System Test > Page 5899 Power Steering Pump: Testing and Inspection Troubleshooting Fig. 1 Troubleshooting power steering system Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Testing and Inspection > Power Steering System Test > Page 5900 Fig. 1 Troubleshooting power steering system Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Testing and Inspection > Power Steering System Test > Page 5901 Fig. 1 Troubleshooting power steering system Refer to figures 1.1 through 1.3 when troublshooting power steering pump. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Service and Repair > Removal/Installation Power Steering Pump: Service and Repair Removal/Installation 1. Disconnect battery ground cable, then place suitable drain pan under pump. 2. Loosen belt tensioner, then remove belt. 3. Remove rear brace attaching nuts, then the rear brace. 4. Remove pulley using puller tool No. J-29785-A, or equivalent. 5. Disconnect and cap pressure and return hoses. 6. Remove pump attaching bolts, then the pump. 7. Reverse procedure to install. Tighten mounting bolts, rear brace to stud nut and brace to pump nut to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Service and Repair > Removal/Installation > Page 5904 Power Steering Pump: Service and Repair Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return line at pump reservoir inlet connector, then plug inlet connector port on pump reservoir. 3. Position fluid return line in large container. 4. While a second person fills reservoir with power steering fluid, run engine at idle. 5. Turn steering wheel from stop to stop. CAUTION: Do not contact wheel stops or hold wheel near a stop position or fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 6. Install any lines, hoses or components removed from vehicle, then fill system with new power steering fluid and bleed system. Refer to System Bleeding. 7. Operate engine for approximately 15 minutes, then remove pump return line at pump inlet and plug connection on pump. 8. While refilling reservoir, check draining fluid for contamination. If any foreign material is present, replace all lines and disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Service and Repair > Removal/Installation > Page 5905 Power Steering Pump: Service and Repair Power Steering Pump Overhaul Disassembly Fig. 2 Exploded view of power steering pump CAUTION: Before disassembly of pump, remove filler cap and drain fluid. If broken components or foreign materials are found during disassembly, hydraulic system should be disassembled, inspected, cleaned and flushed before servicing is complete. 1. Clean exterior of pump with solvent and crocus cloth. 2. Remove bolt and fitting from rear of pump reservoir, then the reservoir and seals. 3. Remove end plate retaining ring using a screwdriver and punch. 4. Remove endplate and pressure plate spring, then the O-ring, control valve and control valve spring by inverting housing. 5. Tap lightly on driveshaft with a rubber mallet to remove pressure plate. 6. Pull out pump ring and vanes, then remove shaft retaining ring, pump rotor and thrust plate. 7. Remove driveshaft key from slot in shaft, then with end of shaft pointed downward, press down until shaft is free. 8. Remove seals, dowel pins and O-rings. Inspection 1. Clean all parts with solvent and blow dry. 2. Check vane tips for scoring or wear. Vanes must fit snugly but slide freely in slots of rotor. Examine rotor slots for burrs and excessive wear at thrust faces. 3. Check inner surface of pump ring for scoring or wear and thrust plate and pressure plate for wear on plate surfaces. 4. If heavy wear is evident in any of above components, replace entire rotating group. 5. Inspect seal for leakage, cracking or swelling, if evident replace seal. 6. Check driveshaft for excessive burning or scoring. 7. Control valve must move smoothly in the valve bore. Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Power Steering > Power Steering Pump > Component Information > Service and Repair > Removal/Installation > Page 5906 Fig. 2 Exploded view of power steering pump 1. Lubricate O-rings, pump ring, rotor and vanes with power steering fluid. 2. Install O-rings and dowel pins on pump housing. 3. Using a seal installation tool, insert seal into front of housing. 4. Install driveshaft and thrust plate. Ensure counterbore faces driveshaft end of housing and install rotor. 5. Insert vanes into rotor, ensuring rounded edge faces away from rotor. 6. Install shaft retaining ring, pump ring and pressure plate. 7. Insert control valve spring, then install control valve and O-ring. 8. Install pressure plate spring and end plate, then secure with end plate retaining ring. 9. Connect seal and reservoir, then install bolt and fitting. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 5912 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Restraint Systems/Air Bag Systems/Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 5913 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 56-32-02B > Sep > 97 > Steering Column Intermittent Click Noise/Snap Steering Column Bearing: Customer Interest Steering Column - Intermittent Click Noise/Snap File In Section: 3 - Steering/Suspension Bulletin No.: 56-32-02B Date: September, 1997 Subject: Intermittent Steering Column Snap or Click Noise when Turning (Install New Upper Bearing Spring) Models: 1994-96 Buick Century, LaSabre, Park Avenue, Regal, Roadmaster 1995-96 Buick Riviera 1994-96 Cadillac Concours, DeVille, Eldorado, Fleetwood, Seville 1994-96 Chevrolet Camaro, Caprice, Corvette, Lumina, Lumina APV 1995-96 Chevrolet Monte Carlo 1994-96 Oldsmobile Cutlass Ciera, Cutlass Supreme, Eighty Eight, Ninety Eight, Silhouette 1995-96 Oldsmobile Aurora 1994-96 Pontiac Bonneville, Firebird, Grand Prix, Trans Sport with Tilt Steering Columns 1995-96 Chevrolet and GMC C/K, S/T Trucks 1994-96 Chevrolet and GMC M/L, G Vans with Tilt Steering Columns This bulletin is being revised to correct the truck models and part number descriptions. Please discard Corporate Bulletin Number 56-32-02A, dated April, 1996 (Section 3 Steering/Suspension). Condition Some owners may comment on an intermittent steering column snap or click noise while turning. The snapping or clicking may also be felt in the steering wheel. Cause The upper bearing race seat may, under some turning conditions, move in an axial direction along the upper steering shaft. The noise is a result of the inner race seat hanging up on the shaft and then suddenly releasing causing a snapping or clicking noise. Correction A new upper bearing spring with increased stiffness has been developed and should- be installed in the steering column. The new spring will increase the preload between the upper bearing inner race seat and the upper steering shaft. To accommodate the new spring with increased stiffness, the cancel cam will also need to be replaced. The new spring and cancel cam, along with a retainer ring and an upper bearing inner race seat are included in the parts kit listed below. Service Procedure Follow the instructions given in Section 3F5 of the appropriate Service Manual and those contained in kit. Be sure to use all parts supplied in the service kit. Parts Information Part Number Description 26059701 1994-96 A/B/C/D/E/F/H/K/U/W 26059701 1994-95 M/L/G Vans 26059702 1995-96 Buick "G" 26059703 1995-96 Oldsmobile "G" 26059704 1995-96 C/K, S/T Truck 26059704 1996 MIL/G Vans (both styles of G Van) 26059705 1994-96 "Y" Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > Customer Interest: > 56-32-02B > Sep > 97 > Steering Column Intermittent Click Noise/Snap > Page 5922 Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 56-32-02B > Sep > 97 > Steering Column - Intermittent Click Noise/Snap Steering Column Bearing: All Technical Service Bulletins Steering Column - Intermittent Click Noise/Snap File In Section: 3 - Steering/Suspension Bulletin No.: 56-32-02B Date: September, 1997 Subject: Intermittent Steering Column Snap or Click Noise when Turning (Install New Upper Bearing Spring) Models: 1994-96 Buick Century, LaSabre, Park Avenue, Regal, Roadmaster 1995-96 Buick Riviera 1994-96 Cadillac Concours, DeVille, Eldorado, Fleetwood, Seville 1994-96 Chevrolet Camaro, Caprice, Corvette, Lumina, Lumina APV 1995-96 Chevrolet Monte Carlo 1994-96 Oldsmobile Cutlass Ciera, Cutlass Supreme, Eighty Eight, Ninety Eight, Silhouette 1995-96 Oldsmobile Aurora 1994-96 Pontiac Bonneville, Firebird, Grand Prix, Trans Sport with Tilt Steering Columns 1995-96 Chevrolet and GMC C/K, S/T Trucks 1994-96 Chevrolet and GMC M/L, G Vans with Tilt Steering Columns This bulletin is being revised to correct the truck models and part number descriptions. Please discard Corporate Bulletin Number 56-32-02A, dated April, 1996 (Section 3 Steering/Suspension). Condition Some owners may comment on an intermittent steering column snap or click noise while turning. The snapping or clicking may also be felt in the steering wheel. Cause The upper bearing race seat may, under some turning conditions, move in an axial direction along the upper steering shaft. The noise is a result of the inner race seat hanging up on the shaft and then suddenly releasing causing a snapping or clicking noise. Correction A new upper bearing spring with increased stiffness has been developed and should- be installed in the steering column. The new spring will increase the preload between the upper bearing inner race seat and the upper steering shaft. To accommodate the new spring with increased stiffness, the cancel cam will also need to be replaced. The new spring and cancel cam, along with a retainer ring and an upper bearing inner race seat are included in the parts kit listed below. Service Procedure Follow the instructions given in Section 3F5 of the appropriate Service Manual and those contained in kit. Be sure to use all parts supplied in the service kit. Parts Information Part Number Description 26059701 1994-96 A/B/C/D/E/F/H/K/U/W 26059701 1994-95 M/L/G Vans 26059702 1995-96 Buick "G" 26059703 1995-96 Oldsmobile "G" 26059704 1995-96 C/K, S/T Truck 26059704 1996 MIL/G Vans (both styles of G Van) 26059705 1994-96 "Y" Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 56-32-02B > Sep > 97 > Steering Column - Intermittent Click Noise/Snap > Page 5928 Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance Windshield: All Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance > Page 5934 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 00-08-48-005D > Sep > 10 > Body - Vehicle Glass Distortion Information Windshield: All Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter Windshield: All Technical Service Bulletins Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter > Page 5943 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 09-08-48-002A > Mar > 09 > Body - Marks/Stains on Windshield When Wet Windshield: All Technical Service Bulletins Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit Windshield: All Technical Service Bulletins New Windshield/Glass Urethane Adhesive Caulking Kit File In Section: 10 - Body Bulletin No.: 83-15-16 Date: October, 1998 INFORMATION Subject: New Windshield and Stationary Glass Urethane Adhesive Caulking Kit Models: 1990-99 All Passenger Cars and Trucks As a result of a change from standard viscosity urethane to high-viscosity urethane, a new Urethane Adhesive Caulking Kit, P/N 12346392, is now available from GMSPO. This kit contains the "High Viscosity" Urethane Adhesive for thicker and more consistent bead size applications. When applied properly, this new high viscosity urethane in many instances will eliminate the need for depth setting blocks or the damming material to control squeeze out. The following is the contents of the new kit: Like the standard viscosity urethane contained in kit (P/N 12346284) that it replaces, it is a one-part, moisture cure product with curing times that vary as a result of changes in either temperature or humidity. THE REQUIRED TIME FOR THIS NEW ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer, IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. Alternate equivalent materials for this kit may be available from a local glass repair shop under the following product numbers: Other manufacturers of Urethane Adhesive that have documented their ability to meet or exceed General Motors specification # 3651M (Performance Requirements for Stationary Glass Bonding Adhesive System Service) are also considered to be equivalent to GM Kit (P/N 12346392). In previously published Corporate Bulletin Number 73-10-54, increasing customer demands for faster service have resulted in quicker two-part urethane adhesives to be made available. Essex Beta Seal U216* (two-part urethane adhesive) also meets the General Motors 3651M Specification and can be Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit > Page 5952 used when the customer demands quicker repair of the vehicle than the above described one-part product can provide. This two-part, chemical cure product requires ONE (1) TO ONE-AND-ONE-HALF (1-1/2) HOURS FOR CURING BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This two-part product also requires primers on the glass and pinchweld surfaces. The primers and applicator daubers are not included with this two-part product and therefore, must be purchased separately. In addition, this two-part product requires a special applicator (gun) for proper mixing and dispensing of the adhesive. Important: The U216 product is NOT available from GMSPO and must be obtained locally. * We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. When using either of the above described products, make sure to follow the manufacturer's directions for application and drying times. For information regarding the removal and installation of stationary glass, consult the appropriate Service Manual. Parts information P/N Description 12346392 Urethane Adhesive Caulking Kit Parts are expected to be available from GMSPO, 10/12/98. Important: The previously recommended adhesive kit (P/N 12346284) will no longer be available from GMSPO once inventory is exhausted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 72-05-04 > Aug > 97 > Warranty - Guidelines for Claiming Windshield Replace Windshield: All Technical Service Bulletins Warranty - Guidelines for Claiming Windshield Replace File In Section: Warranty Administration Bulletin No.: 72-05-04 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Claiming C0034 - Windshield Replacement Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with guidelines for using the above subject labor operations. In an effort to understand the windshield replacements, the following two phase approval process is being implemented. We feel this approach will allow GM to be responsive to repair decisions on vehicles over 10,000 miles (16,000KMS), while providing you, our dealers, the empowerment to address customer needs on those cases requiring repairs early in the vehicle's life, under 10,000 miles (16,000KMS). Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Windshield replacement on vehicles under 10,000 miles (16,0OOKMS) can only be made after Service Management inspection, review and approval. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. ^ Windshield replacement on vehicles over 10,000 miles (16,000KMS) can only be made after Service Management inspection, review and approval from the divisional service representative. Vehicles may be required to be held for wholesale inspection. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. The claim will require wholesale authorization for payment. Additional Requirements ^ Windshields replaced must be held for the normal parts retention period and the defect should be clearly identified on the glass by means of tape and/or a grease pencil. ^ Sublet windshield replacements, like other sublet repairs are to be claimed for actual dealership cost less any discounts and or allowances offered. Sublet repairs cannot exceed the normal allowance provided to the dealership had the repair been completed in-house. See your GM Policy and Procedure Manual for the complete guidelines. Windshields damaged by normal wear, road hazards, vandalism, or other physical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 73-10-54 > May > 97 > Windshield - Two-Part Urethane Adhesive For Installation Windshield: All Technical Service Bulletins Windshield - Two-Part Urethane Adhesive For Installation File In Section: 10 - Body Bulletin No.: 73-10-54 Date: May, 1997 INFORMATION Subject: Two-Part Urethane Adhesive For Windshield Installations Models: 1997 And Prior Passenger Cars and Trucks (Using Urethane Adhesive To Retain Windshields) General Motors passenger cars and trucks use urethane adhesive as a means to retain the windshield in the body opening. The urethane adhesive is used to bond the windshield in the opening, increasing vehicle structure. The current recommended urethane adhesive, GM P/N 12346284, is a one-part moisture cure product that requires a minimum curing period of 6 hours at room temperature before returning the vehicle to the customer. Increasing customer demands for faster service in recent years have resulted in quicker cure two-part urethane adhesives. Essex Beta Seal U216* (two-part urethane adhesive) meets the General Motors 3651M Specification (Performance Requirements for Stationary Glass Bonding Adhesive System Service) and can be used when the customer demands quicker repair of the vehicle than the current one-part materials can provide. Either of these products can be used when glass replacement is performed. The differences between these products are as follows: The CURRENT URETHANE ADHESIVE KIT, GM P/N 12346284, IS A ONE-PART ADHESIVE. It includes the necessary glass and pinchweld primers and is specified in Service Manuals for General Motors' vehicles. Since this is a "moisture cure" product, the curing time for this one-part material will vary with changes to either temperature or humidity. The REQUIRED TIME FOR THIS ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. ESSEX BETA SEAL U216 IS A TWO-PART ADHESIVE MATERIAL THAT PROVIDES FOR A ONE (1) TO ONE AND ONE HALF (11/2) HOUR CURE BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This product also requires primers on the glass and pinchweld surfaces. This product requires a special applicator for the mixing and dispensing of the adhesive. When using this (or any) product, make sure to follow the manufacturer's directions for application and drying times. Parts Information Parts are currently available from GMSPO. * We believe this source and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance > Page 5966 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter > Page 5975 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Column > Steering Column Bearing > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Column Bearing: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit > Page 5984 used when the customer demands quicker repair of the vehicle than the above described one-part product can provide. This two-part, chemical cure product requires ONE (1) TO ONE-AND-ONE-HALF (1-1/2) HOURS FOR CURING BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This two-part product also requires primers on the glass and pinchweld surfaces. The primers and applicator daubers are not included with this two-part product and therefore, must be purchased separately. In addition, this two-part product requires a special applicator (gun) for proper mixing and dispensing of the adhesive. Important: The U216 product is NOT available from GMSPO and must be obtained locally. * We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. When using either of the above described products, make sure to follow the manufacturer's directions for application and drying times. For information regarding the removal and installation of stationary glass, consult the appropriate Service Manual. Parts information P/N Description 12346392 Urethane Adhesive Caulking Kit Parts are expected to be available from GMSPO, 10/12/98. Important: The previously recommended adhesive kit (P/N 12346284) will no longer be available from GMSPO once inventory is exhausted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Customer Interest: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve Steering Gear: Customer Interest P/S - Hissing Noise From Gear, Redesigned Spool Valve Group Ref.: Steering/Suspension Bulletin No.: 363201 Date: February, 1994 SUBJECT: POWER STEERING GEAR HISS (REPLACE POWER STEERING VALVE ASSEMBLY) MODELS: 1985-93 CHEVROLET AND GMC M VANS 1990-93 CHEVROLET AND GMC L VANS THIS BULLETIN IS BEING REVISED TO ADD INFORMATION ON PITMAN SHAFT OVER-CENTER PRELOAD ADJUSTMENT. PREVIOUS DIVISIONAL PUBLICATION NUMBER WAS: DIVISION BULLETIN NUMBER CHEVROLET 93-128-3B CONDITION: Some owners may comment that a hissing noise can be heard emanating from the power steering gear during parking lot type maneuvers. CAUSE: The hiss condition is caused by the cavitation (high pressure/velocity) of the power steering fluid as it passes through the closing edges of the spool valve contained within the power steering gear. This condition is inherent to the gear design and poses no threat to steering system integrity, performance or durability. CORRECTION: To minimize this condition, a newly designed spool valve (part number 26036745) has been released for service only. The new spool valve will reduce the amount of cavitation (hiss) of the fluid. SERVICE PROCEDURE: Remove: 1. Power steering gear from the vehicle (Figure 1). - Refer to Section 3B1 of the appropriate M/L van Service Manual for complete removal instructions of the power steering gear from the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Customer Interest: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6001 2. Adjuster plug locknut (245) from the steering gear (Figure 2). Note: Care should be taken not to raise a burr on the back of the lock nut (245) during removal. A burr may cause a problem with perceived valve effort after reassembly, if it is severe enough to cock the valve in the bore. 3. Adjuster plug valve assembly (240) using J7624 (Figure 3). 4. Remove the steering valve (250) and stub shaft assembly from the power steering gear housing (Figure 1). Important: Removal of the steering valve (Figure 4, Item 250) and stub shaft should be done by pulling straight out from the power steering gear housing bore. Do not remove the worm shaft (248) and thrust gearing assembly (246, 247) when removing the steering valve assembly. Removing the worm shaft Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Customer Interest: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6002 will result in one or more balls dropping out of the steering worm circuit. Loss of any balls in the circuit will require a complete rebuilding of the steering rack and worm assembly. Install: Important: The valve body assembly, rings and all seals should be lubricated with power steering fluid before assembly. 1. Install new steering valve assembly P/N 26036745 (250) (Figure 1). Note: Pin (A) on the worm gear (248) lines up with slot (B) in the steering valve assembly (250) (Figure 4). When installing adjuster plug (240), care should be taken not to cut the seals. 2. Adjuster plug assembly (240) using J7624 (Figure 3). Adjust (Figure 5, steps A through E) Bearing preload a. Before adjusting bearing preload, rotate the stub shaft back and forth to drain all oil from the gear (Figure 5, A). b. Use tool J7624. Turn the adjuster plug (240) to the left until the plug assembly is firmly bottomed to 30 N-m (22 lbs.ft.) (Figure 5, B). c. Mark the housing in line with one of the holes in the adjuster plug (Figure 5, C). d. Measure back (to the left) 13 mm (1/2 inch) and remark the housing (Figure 5, C). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Customer Interest: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6003 e. Rotate the adjuster to the left until the hole in the adjuster is in line with the second mark (Figure 5, D). f. Install adjuster plug locknut (245) and tighten securely by lightly tapping a brass punch into one of the notches in the adjuster nut with a hammer (Figure 5, E). g. Hold the adjuster plug to maintain alignment of the hole with the mark. 3. Pitman shaft over-center preload adjustment (Figures 6 through 8). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Customer Interest: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6004 a. Using a 12 point socket and wrench, rotate the stub shaft from stop to stop and count the number of turns. b. Starting at either stop, turn the stub shaft back 1/2 the total number of turns. This is the "center" of the gear. When the gear is centered, the flat on the stub shaft (Figure 7, Item 40) should face upward and be in parallel with the side cover (Figure 7, Item A) and the master spline (Figure 6, Item B) on the pitman shaft should be in line with the adjuster screw (Figure 6, Item B). c. Turn the pitman shaft adjuster screw (Figure 6, Item B) counter-clockwise until fully extended, then turn back in one full turn. d. Check the turning torque of the stub shaft using an inch pound torque wrench and 12 point socket. Place the torque wrench, in the vertical position on the stub shaft. Rotate the torque wrench 45 degrees each side of the center of the stub shaft and record the highest drag torque measured on or near center (Figure 8). e. Turn the adjuster screw in until the torque required to turn the stub shaft is 0.6 to 1.2 N-m (6.0 10.0 lbs.in.) greater than the reading in step "d". Tighten the adjuster screw jam nut to 50 N-m (37 lbs.ft.). 4. Steering gear to vehicle. Refer to "Power Steering Gear Replacement" in Section 3B of the appropriate M/L Service Manual for complete installation and system bleed procedure. SERVICE PARTS INFORMATION Part Number Description Quantity 26036745 Valve Assembly 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use (see illustration). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 83-32-10 > Nov > 98 > Tools - Adjuster Locknut Wrench Steering Gear: All Technical Service Bulletins Tools - Adjuster Locknut Wrench File In Section: 3 - Steering/Suspension Bulletin No.: 83-32-10 Date: November, 1998 INFORMATION Subject: Essential Tool J 43435 Adjuster Locknut Wrench Models: 1990-99 Passenger Cars and Trucks with Integral Power Steering A new essential tool, J 43435 Adjuster Locknut Wrench, has been sent to all GM Dealers. This tool should be used on all Integral power steering gears, both past and current models. The following procedure should be used In place of existing Service Manual procedures for Coupling Shield and Locknut Removal and Replacement. The correct adjustment procedure and use of the essential tools are critical to restore the vehicle "On Center" feel (See Figure 1). Important: Coupling shield retainer and locknut assembly replacement procedures require the following special tools: J 42882 Adjuster Nut Wrench J 43435 Adjuster Locknut Wrench Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 83-32-10 > Nov > 98 > Tools - Adjuster Locknut Wrench > Page 6010 (See Figure 2) Procedure 1. Place J 42882 over the end of the stub shaft. Place J 43435 over the end. J 43435 is reversible and can be used with both old and new style coupling shield retainers and locknuts. 2. Tighten the coupling shield retainer and locknut assembly after an adjustment or repair has been made to the power steering gear to the specified torque (See Figure 3). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve Steering Gear: All Technical Service Bulletins P/S - Hissing Noise From Gear, Redesigned Spool Valve Group Ref.: Steering/Suspension Bulletin No.: 363201 Date: February, 1994 SUBJECT: POWER STEERING GEAR HISS (REPLACE POWER STEERING VALVE ASSEMBLY) MODELS: 1985-93 CHEVROLET AND GMC M VANS 1990-93 CHEVROLET AND GMC L VANS THIS BULLETIN IS BEING REVISED TO ADD INFORMATION ON PITMAN SHAFT OVER-CENTER PRELOAD ADJUSTMENT. PREVIOUS DIVISIONAL PUBLICATION NUMBER WAS: DIVISION BULLETIN NUMBER CHEVROLET 93-128-3B CONDITION: Some owners may comment that a hissing noise can be heard emanating from the power steering gear during parking lot type maneuvers. CAUSE: The hiss condition is caused by the cavitation (high pressure/velocity) of the power steering fluid as it passes through the closing edges of the spool valve contained within the power steering gear. This condition is inherent to the gear design and poses no threat to steering system integrity, performance or durability. CORRECTION: To minimize this condition, a newly designed spool valve (part number 26036745) has been released for service only. The new spool valve will reduce the amount of cavitation (hiss) of the fluid. SERVICE PROCEDURE: Remove: 1. Power steering gear from the vehicle (Figure 1). - Refer to Section 3B1 of the appropriate M/L van Service Manual for complete removal instructions of the power steering gear from the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6015 2. Adjuster plug locknut (245) from the steering gear (Figure 2). Note: Care should be taken not to raise a burr on the back of the lock nut (245) during removal. A burr may cause a problem with perceived valve effort after reassembly, if it is severe enough to cock the valve in the bore. 3. Adjuster plug valve assembly (240) using J7624 (Figure 3). 4. Remove the steering valve (250) and stub shaft assembly from the power steering gear housing (Figure 1). Important: Removal of the steering valve (Figure 4, Item 250) and stub shaft should be done by pulling straight out from the power steering gear housing bore. Do not remove the worm shaft (248) and thrust gearing assembly (246, 247) when removing the steering valve assembly. Removing the worm shaft Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6016 will result in one or more balls dropping out of the steering worm circuit. Loss of any balls in the circuit will require a complete rebuilding of the steering rack and worm assembly. Install: Important: The valve body assembly, rings and all seals should be lubricated with power steering fluid before assembly. 1. Install new steering valve assembly P/N 26036745 (250) (Figure 1). Note: Pin (A) on the worm gear (248) lines up with slot (B) in the steering valve assembly (250) (Figure 4). When installing adjuster plug (240), care should be taken not to cut the seals. 2. Adjuster plug assembly (240) using J7624 (Figure 3). Adjust (Figure 5, steps A through E) Bearing preload a. Before adjusting bearing preload, rotate the stub shaft back and forth to drain all oil from the gear (Figure 5, A). b. Use tool J7624. Turn the adjuster plug (240) to the left until the plug assembly is firmly bottomed to 30 N-m (22 lbs.ft.) (Figure 5, B). c. Mark the housing in line with one of the holes in the adjuster plug (Figure 5, C). d. Measure back (to the left) 13 mm (1/2 inch) and remark the housing (Figure 5, C). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6017 e. Rotate the adjuster to the left until the hole in the adjuster is in line with the second mark (Figure 5, D). f. Install adjuster plug locknut (245) and tighten securely by lightly tapping a brass punch into one of the notches in the adjuster nut with a hammer (Figure 5, E). g. Hold the adjuster plug to maintain alignment of the hole with the mark. 3. Pitman shaft over-center preload adjustment (Figures 6 through 8). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Steering Gear: > 363201 > Feb > 94 > P/S - Hissing Noise From Gear, Redesigned Spool Valve > Page 6018 a. Using a 12 point socket and wrench, rotate the stub shaft from stop to stop and count the number of turns. b. Starting at either stop, turn the stub shaft back 1/2 the total number of turns. This is the "center" of the gear. When the gear is centered, the flat on the stub shaft (Figure 7, Item 40) should face upward and be in parallel with the side cover (Figure 7, Item A) and the master spline (Figure 6, Item B) on the pitman shaft should be in line with the adjuster screw (Figure 6, Item B). c. Turn the pitman shaft adjuster screw (Figure 6, Item B) counter-clockwise until fully extended, then turn back in one full turn. d. Check the turning torque of the stub shaft using an inch pound torque wrench and 12 point socket. Place the torque wrench, in the vertical position on the stub shaft. Rotate the torque wrench 45 degrees each side of the center of the stub shaft and record the highest drag torque measured on or near center (Figure 8). e. Turn the adjuster screw in until the torque required to turn the stub shaft is 0.6 to 1.2 N-m (6.0 10.0 lbs.in.) greater than the reading in step "d". Tighten the adjuster screw jam nut to 50 N-m (37 lbs.ft.). 4. Steering gear to vehicle. Refer to "Power Steering Gear Replacement" in Section 3B of the appropriate M/L Service Manual for complete installation and system bleed procedure. SERVICE PARTS INFORMATION Part Number Description Quantity 26036745 Valve Assembly 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use (see illustration). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Gear: > 83-32-10 > Nov > 98 > Tools - Adjuster Locknut Wrench Steering Gear: All Technical Service Bulletins Tools - Adjuster Locknut Wrench File In Section: 3 - Steering/Suspension Bulletin No.: 83-32-10 Date: November, 1998 INFORMATION Subject: Essential Tool J 43435 Adjuster Locknut Wrench Models: 1990-99 Passenger Cars and Trucks with Integral Power Steering A new essential tool, J 43435 Adjuster Locknut Wrench, has been sent to all GM Dealers. This tool should be used on all Integral power steering gears, both past and current models. The following procedure should be used In place of existing Service Manual procedures for Coupling Shield and Locknut Removal and Replacement. The correct adjustment procedure and use of the essential tools are critical to restore the vehicle "On Center" feel (See Figure 1). Important: Coupling shield retainer and locknut assembly replacement procedures require the following special tools: J 42882 Adjuster Nut Wrench J 43435 Adjuster Locknut Wrench Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > All Other Service Bulletins for Steering Gear: > 83-32-10 > Nov > 98 > Tools - Adjuster Locknut Wrench > Page 6024 (See Figure 2) Procedure 1. Place J 42882 over the end of the stub shaft. Place J 43435 over the end. J 43435 is reversible and can be used with both old and new style coupling shield retainers and locknuts. 2. Tighten the coupling shield retainer and locknut assembly after an adjustment or repair has been made to the power steering gear to the specified torque (See Figure 3). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Page 6025 Steering Gear: Specifications Component .......................................................................................................................................... ..................................................................... Ft. Lbs. Adjuster Jam Nut ................................................................................................................................. ............................................................................... 37 Adjuster Plug .................................................. .............................................................................................................................................................. ...... 20 Gear To Frame Bolts ............................................................................................................... ........................................................................................... 55 Intermediate Shaft Yoke Bolt .............. .............................................................................................................................................................. ................. 29 Power Steering Cooler Bracket .................................................................................... ...................................................................................................... 18 Power Steering Hose Clamp [01] ....................................................................................................................................................... ................................ 18 Power Steering Hose To Steering Gear Adapter Pipe ........................................................................................................................................................ 21 Power Steering Pressure Hose Flare Nut ........................................................................................... ................................................................................. 18 Pump Mounting Bolts ................................... .............................................................................................................................................................. ....... 37 Remote Reservoir Mounting Bolts [01] ................................................................................... .......................................................................................... 35 Reservoir To Steering Pump Housing Clamps [01] ........................................................................................................................................................... 35 [01] Inch lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Page 6026 Steering Gear: Application and ID This vehicle uses a Saginaw 708 series integral power steering gear. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Technical Service Bulletins > Page 6027 Steering Gear: Description and Operation Fig. 1 Exploded view of power steering gear The power steering gear has a recirculating ball system which acts as a rolling thread between the worm shaft and the rack piston. The worm shaft is supported by a thrust bearing preload and two conical thrust races at the lower end, and a bearing assembly in the adjuster plug at the upper end. The control valve in the steering gear directs the power steering fluid to either side of the rack piston. The rack piston converts the hydraulic pressure into a mechanical force. If the steering system loses hydraulic pressure, the vehicle can be controlled manually. When the worm shaft is turned right, the rack piston moves up in the gear while turning left moves the rack piston down in the gear. The rack piston teeth mesh with the pitman shaft sector. Turning the worm shaft turns the pitman shaft, which turns the wheels through the steering linkage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures Steering Gear: Symptom Related Diagnostic Procedures Fig. 1 Troubleshooting power steering system Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures > Page 6030 Fig. 1 Troubleshooting power steering system Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures > Page 6031 Fig. 1 Troubleshooting power steering system Refer to figures when troubleshooting power steering pump. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures > Page 6032 Steering Gear: Component Tests and General Diagnostics NOTE: All tests are made with engine idling at normal operating temperature. Check idle speed adjustment and, if necessary, adjust to correct specification. 1. Place a container under steering gear or pump. 2. With engine Off, disconnect pressure hose at steering gear or power steering pump, then install J-5176-D to both hoses using adapter fitting No. J-5176-20 or equivalent. Gauge must be installed between shutoff valve and pump. 3. Open shutoff valve. 4. Remove filler cap from pump reservoir and check fluid level. Fill pump reservoir with power steering fluid to full mark on dipstick. Start engine and, momentarily holding steering wheel against stop, check connections for leakage. CAUTION: Do not hold wheel against stop for more than five seconds as pump can be damaged internally. 5. Bleed power steering system. 6. Insert thermometer No. J-5421-02 or equivalent in reservoir filler opening. Move steering wheel from stop to stop several times until thermometer indicates that hydraulic fluid in reservoir has reached a temperature of 150-170 °F. CAUTION: To prevent flat spotting tires, do not turn steering wheel more than five times without rolling vehicle to change tire to floor contact area. 7. Check pump fluid level. Add fluid if required. 8. When engine is at normal operating temperature, the initial pressure on gauge (valve open) should be within 80-125 psi. If pressure is in excess of 200 psi., check hoses for restrictions and poppet valve for proper assembly. 9. Open and close gauge valve fully three times. CAUTION: Do not leave valve closed for more than five seconds as pump could be damaged internally. 10. Record highest pressures attained each time. a. If pressures recorded are within specifications, and range of readings is within 50 psi., pump is functioning within specification. b. If pressures recorded are constant but more than 100 psi., below minimum specification, replace flow control valve and recheck. If pressures are still low, replace rotating group in pump. c. If pressure recorded are high, but do not repeat within 50 psi., flow control valve is sticking. Remove and clean valve. Remove any burrs using crocus cloth or fine hone. If system contains some dirt, flush system. If it is exceptionally dirty, both pump and gear must be completely disassembled, cleaned, flushed and reassembled before further use. 11. If pump checks within specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with maximum pump pressure recorded. If maximum pressure cannot be reached in either (or one) side of gear, gear is leaking internally and must be disassembled and repaired. 12. Turn engine Off, remove testing gauge, reconnect pressure hose, check fluid level and/or make needed repairs. 13. If problem still exists, steering and from suspension must be thoroughly examined. Refer to Troubleshooting. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Adjustments > Worm Bearing Preload Steering Gear: Adjustments Worm Bearing Preload Fig. 12 Adjuster plug nut removal 1. Loosen and remove adjuster plug nut. Fig. 4 Adjuster plug removal 2. Turn adjuster plug clockwise using spanner wrench tool J-7624 or equivalent, until plug and thrust bearing are firmly bottomed in housing. 3. Scribe an index mark on the housing even with a hole on adjuster plug. Fig. 13 Adjuster plug alignment mark 4. Measure back 3/16 - 1/4 inch from first index mark and scribe a second index mark. 5. Rotate adjuster plug counterclockwise until hole is aligned with second index mark. 6. Install adjuster plug nut, tighten to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Adjustments > Worm Bearing Preload > Page 6035 Fig. 14 Stub shaft torque reading 7. Using an inch-pound torque wrench and a 12-point deep socket, measure torque required to turn stub shaft. Take reading with handle of torque wrench near vertical position. Turn stub shaft to right stop, then back 1/4 turn at an even rate. Record torque reading. 8. Torque reading should be 4-10 inch lbs. If not, adjuster plug may not be tightened properly or may have turned during adjuster plug nut installation. Thrust bearings and races may also be damaged. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Adjustments > Worm Bearing Preload > Page 6036 Steering Gear: Adjustments Over Center Preload Fig. 15 Stub shaft alignment 1. Turn pitman shaft adjuster screw counterclockwise until fully extended, then reverse 1/2 turn clockwise. 2. Rotate stub shaft from stop to stop and count number of turns. 3. Starting at either stop, turn stub shaft halfway back. When gear is centered, flat on stub shaft will face upward and be parallel with side cover. 4. Place torque wrench on stub shaft and rotate 45° each side of center. Record highest drag torque measured on or near center. 5. Adjust over-center drag torque by loosening adjuster screw jam nut and turning pitman shaft adjuster screw clockwise until correct drag torque is obtained. 6. On new steering gears, add 6-10 inch lbs. torque to previously measured worm bearing preload torque. Do not exceed a total steering gear preload of 18 inch lbs. 7. On used steering gears, add 4-5 inch lbs. torque to previously measured worm bearing preload torque. Do not exceed a total steering gear preload of 14 inch lbs. 8. Install and tighten adjuster screw jam nut to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear Steering Gear: Service and Repair Saginaw Integral Power Steering Gear Component Service If broken components or foreign materials are found during disassembly of the gear, the hydraulic system should be inspected, cleaned and flushed before service is complete. The ball nut and control rings are not generally replaced unless cut or damaged. If replacing, inspect all mating parts for burrs, cracks, scratches or damage. Replace or repair as needed. System Bleeding Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6039 Fig. 2 Power Steering System Bleed Chart 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine OFF. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6040 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. For additional bleed procedures, refer to Fig. 2. Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return line at pump reservoir inlet connector, then plug inlet connector port on pump reservoir. 3. Position fluid return line in large container. 4. While a second person fills reservoir with power steering fluid, run engine at idle. 5. Turn steering wheel from stop to stop. CAUTION: Do not contact wheel stops or hold wheel near a stop position or fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 6. Install any lines, hoses or components removed from vehicle, then fill system with new power steering fluid and bleed system. Refer to System Bleeding. 7. Operate engine for approximately 15 minutes, then remove pump return line at pump inlet and plug connection on pump. 8. While refilling reservoir, check draining fluid for contamination. If any foreign material is present, replace all lines and disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Disassembly Fig. 1 Exploded view of power steering gear 1. Pry retaining ring out of housing groove with a screwdriver. 2. Turn stub shaft to the left until plug on opposite end is forced out of cylinder, then remove seal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6041 Fig. 2 Rack piston plug removal 3. Remove plug from rack piston. 4. Remove nut, bolt, side cover and gasket, then turn adjuster screw right until side cover separates from pitman shaft. 5. Remove piston shaft, then turn stub shaft left until pitman shaft teeth and rack piston disengage. Fig. 3 Bearing removal 6. Remove retaining ring, washers and seals, then remove bearing with bearing removal tool No. J-6278 or equivalent if necessary. 7. Remove rack piston and balls as follows: a. Insert ball retainer tool J-21552 or equivalent into rack piston bore with pilot seated into end of worm. b. Hold tool against worm and turn stub shaft to left. Rack piston will be forced onto the tool. c. Hold tool and pull rack piston toward handle until it is against flange. This will prevent end circuit balls from falling out. Fig. 4 Adjuster plug removal 8. Remove adjuster nut, then remove adjuster plug using spanner wrench tool J-7624 or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6042 Fig. 5 Needle bearing removal 9. Disassemble adjuster plug as follows: a. Remove retaining ring, washer, seal and bearing. b. Remove bearing retainer by prying at raised area, then remove seal and needle bearing with adjuster plug bearing installer tool J-8524-2 and driver tool J-7079-2 or equivalents. Fig. 6 Worm shaft & valve body removal 10. Remove valve and worm shaft as an assembly with both races and bearing. Separate as follows: a. Remove worm shaft from valve body. b. Remove races and bearing from worm shaft, them remove seal. Fig. 7 Stub shaft pin disengage 11. Remove stub shaft from valve body as follows: a. Hold assembly and lightly tap stub shaft against a bench until shaft cap is free from valve body. b. Pull shaft assembly until shaft cap clears valve body by approximately 1/4 inch. c. Remove valve spool and seals. 12. Remove screws, clamp and ball guide from rack piston, then remove balls. 13. Remove connectors from housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6043 Assembly Fig. 8 Connector installation 1. Install connectors using valve connector installer tool J-6217 or equivalent. Fig. 9 Recirculating ball installation Fig. 2 Rack piston plug removal 2. Lubricate 24 balls with power steering fluid, then install alternately by color into rack piston. Use ball retainer tool J-21552 or equivalent, to hold balls inside. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6044 Fig. 10 Ball guide installation 3. Install balls in ball guide alternately by color, retain in guide with petroleum jelly. 4. Connect ball guide, clamp and screws to rack piston. 5. Lubricate stub shaft, valve spool and seals with power steering fluid, then install into valve body. 6. Connect valve body, seal, worm shaft, races and roller bearing. Fig. 11 Needle bearing installation 7. Install seal on adjuster plug, then needle bearing in adjuster plug using J-8524-1 and J-7079-2 or equivalent. 8. Install seal, washer and retaining ring in adjuster plug. CAUTION: Retainer projections must not extend beyond washer when retainer ring is seated. Washer must rotate freely. 9. Install worm shaft and valve assembly into gear housing. Fig. 4 Adjuster plug removal 10. Install adjuster plug into gear housing using spanner wrench tool J-7624 or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Gear > Component Information > Service and Repair > Saginaw Integral Power Steering Gear > Page 6045 Steering Gear: Service and Repair Power Steering Gear Replace 1. Disconnect battery ground cable. 2. Disconnect pressure and return lines from steering gear housing, then plug hose ends and gear housing ports to prevent contamination. 3. Remove pinch bolt from intermediate shaft. 4. Remove the universal yoke from the stub shaft. 5. Remove pitman arm nut and washer from pitman shaft, then mark relationship between shaft and arm for assembly reference. 6. Remove pitman arm using pitman arm remover tool No. J-29107, or equivalent. 7. Remove steering gear frame bolts and washers, then the steering gear. 8. Reverse procedure to install. Tighten intermediate shaft pinch bolt and pitman shaft nut to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Steering > Steering Wheel > Component Information > Service and Repair Steering Wheel: Service and Repair 1. Disconnect battery ground cable. 2. Remove steering wheel shroud attaching screws, if equipped, from underside of steering wheel. 3. Remove cap or lift steering wheel shroud and horn contact lead assembly from steering wheel. 4. Remove retainer, then the steering wheel nut. Mark relationship of steering wheel to steering shaft. 5. Remove steering wheel using puller tool No. J-1859-03, or equivalent. 6. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Ball Joint > Component Information > Testing and Inspection > Upper Ball Joint: Testing and Inspection Upper Fig. 1 Upper Ball Joint Inspection Prior to inspecting ball joints, ensure wheel bearings are properly adjusted. 1. Raise vehicle and position stands under right and left lower control arms near each lower ball joint. Vehicle should not rock while on stands and the upper control arm bumper must not contact frame. 2. Clean and inspect ball joint seals for cuts or tears. If seal is cut or torn, the ball joint must be replaced. 3. Position dial indicator against the lowest outboard point on the wheel rim, Fig. 1. 4. Rock the wheel in and out and observe gauge. Horizontal deflection should not exceed 0.125 inch. 5. If reading exceeds specification, or if ball stud had been disconnected from knuckle assembly and any looseness is evident, or if stud can be turned by hand, replace ball joint. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Ball Joint > Component Information > Testing and Inspection > Upper > Page 6054 Ball Joint: Testing and Inspection Lower Fig. 2 Lower Ball Joint Wear Indicators Prior to inspecting ball joints, ensure wheel bearings are properly adjusted. The lower ball joint is equipped with a visual wear indicator, Fig. 2. Check ball joint with vehicle weight resting on wheels. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Ball Joint > Component Information > Service and Repair > Upper Ball Joint Replacement Ball Joint: Service and Repair Upper Ball Joint Replacement 1. Raise and support vehicle. Support lower control arm with suitable jack stands. Jack must be positioned between coil spring seat and ball joint of lower control arm to obtain maximum leverage against coil spring pressure. 2. Remove wheel and tire assembly, then the ball joint cotter pin, stud nut and grease fitting. 3. Break stud loose from steering knuckle using ball joint separator tool No. J-23742, or equivalent. Apply pressure on stud by expanding tool until stud breaks free. 4. Support the steering knuckle to prevent damage to brake hoses. 5. With control arm in raised position, drill rivets 1/4 inch deep with a 1/8 inch drill, then drill off rivet heads with a 1/2 inch drill. 6. Punch out rivets, then remove ball joints. 7. Reverse procedure to install. Replace rivets with attaching bolts and nuts. Tighten retaining nuts and bolts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Ball Joint > Component Information > Service and Repair > Upper Ball Joint Replacement > Page 6057 Ball Joint: Service and Repair Lower Ball Joint Replacement LOWER BALL JOINT REPLACEMEMT - Tools Required: J 36202 Torsion Bar Unloading Tool - J 29193 Steering Linkage Installer - J 35917 Ball Joint Remover - Or Equivalent REMOVE OR DISCONNECT - Raise the vehicle and support it with safety stands. 1. Tire and wheel. 2. Front splash shield. - Remove two bolts and pivot the shield in order to gain access to the tie rods. 3. Inner tie rod end from the relay. 4. Drive axle shaft nut and washer from the hub assembly. 5. Bolts from hub end bearing kit. 6. Ball joint cotter pin (9). 7. Ball joint nut. 8. Unload the torsion bar, using J 36202. - Mark adjuster bolt for loading the torsion bar. - Support the lower control arm with a safety stand. 9. Knuckle from the ball joint, using J 35917. 10. Rivets. a. Center punch the bottom of the rivets. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Ball Joint > Component Information > Service and Repair > Upper Ball Joint Replacement > Page 6058 b. Using a 3 mm (1/8 inch) drill bit, drill a guide hole 13 mm (1/2 inch) into the rivet heads. c. Using an 8 mm (5/16 inch) drill bit, drill the rivet head off. Drill a hole two-thirds the length of the rivet shank, using a 5/16 inch drill. d. Using an 8 mm (5/16) pin punch, punch out the rivets. 11. Ball joint. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Ball Joint > Component Information > Service and Repair > Upper Ball Joint Replacement > Page 6059 INSTALL OR CONNECT 1. Ball joint to the control arm. 2. Bolts (A), flat washers (B), and nuts (C) to the ball joint. Tighten (c) to 30 Nm (22 ft. lbs.). 3. Ball joint to the knuckle. - Raise lower control arm with the hydraulic jack. 4. Nut. - Tighten Nut to 128 Nm (95 ft. lbs.). - Nut must be tightened with the control arm at the "Z" height. - Tighten the nut to align the cotter pin. Do not tighten more than 1/6 turn. 5. New cotter pin (9). - Bend the pin ends against the nut. 6. Load the torsion bar, using J 36202. - Set the adjuster bolt at the mark made during disassembly. 7. Hub and bearing kit to knuckle. 8. Bolts. Tighten to 90 Nm (66 ft. lbs.). 9. Drive axle to the hub and bearing kit. 10. Washer and nut. Tighten to 200 Nm (147 ft. lbs.). 11. Inner tie rod end to the relay rod. 12. Inner tie rod end nut. 13. Front splash shield. 14. Front splash shield bolts. 15. Tire and wheel. 16. Wheel lug nuts. - Lower the vehicle. - Check the front wheel alignment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Control Arm > Control Arm Bushing > Component Information > Service and Repair > Upper Control Arm Bushing Control Arm Bushing: Service and Repair Upper Control Arm Bushing Fig. 2 Upper Control Arm Bushing Removal Fig. 3 Upper Control Arm Bushing Installation 1. Remove upper control arm. 2. Place upper control arm in a vise, then remove nuts from end of pivot shaft. 3. Press bushings out of control arm using control arm bushing installer tool No. J-22269, or equivalent, Fig. 10. 4. Remove the bushing from the pivot shaft. 5. Position pivot shaft in control arm and press new bushings into control arm and over pivot shaft, Fig. 11.Both bushings must be installed 0.48-0.52 inch from face of control arm to bushing outer sleeve. 6. Install pivot shaft retaining nuts and tighten to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Control Arm > Control Arm Bushing > Component Information > Service and Repair > Upper Control Arm Bushing > Page 6065 Control Arm Bushing: Service and Repair Lower Control Arm & Bushing 1. Remove lower control arm. Fig. 5 Lower Control Arm Front Bushing Removal Fig. 13 Lower Control Arm Rear Bushing Removal 2. Drive bushing flare down flush with rubber of front bushing, then remove front and rear bushings from control arm, Fig 2. 12 and 13. Fig. 7 Lower Control Arm Front Bushing Installation Fig. 15 Lower Control Arm Front Bushing Flare Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Control Arm > Control Arm Bushing > Component Information > Service and Repair > Upper Control Arm Bushing > Page 6066 3. Install front bushing, Fig. 14, then flare the bushing, Fig. 15. Fig. 16 Lower Control Arm Rear Bushing Installation 4. Install rear bushing, Fig. 16, then the lower control arm. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Front Steering Knuckle > Component Information > Service and Repair Front Steering Knuckle: Service and Repair Fig. 17 Steering Knuckle Replacement 1. Raise front of vehicle and support with jack stands under front lift points, then remove wheel and tire assembly. Do not support vehicle under lower control arm at this time, as vehicle may slip off stands during knuckle removal. Spring tension will also aid in breaking ball joint studs loose from steering knuckle. 2. Remove brake caliper, then the brake and hub assembly. 3. Remove splash shield-to-steering knuckle attaching bolts. 4. Remove tie rod end from steering knuckle using tie rod end puller tool No. J-6627, or equivalent. 5. If steering knuckle is to be repaired or replaced, remove knuckle seal. 6. Remove ball joint studs from steering knuckle using ball joint remover tool No. J-23742, or equivalent. 7. Position a suitable jack under lower control arm near spring seat, then raise jack until it just supports control arm. Jack must remain in position under control arm during removal and installation to hold spring and control arm in position. 8. Raise upper control arm to disengage upper ball joint stud from knuckle. 9. Remove steering knuckle from lower ball joint stud, Fig. 17. 10. After removal, inspect and clean tapered hole in steering knuckle. If hole is out of round or damaged in any way, then knuckle must be replaced. 11. Reverse procedure to install. Tighten upper ball joint nut, lower ball joint nut, splash shield attaching bolts and tie rod end to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Stabilizer Bar, Sway Control > Component Information > Service and Repair > Front Suspension Stabilizer Bar: Service and Repair Front Suspension Fig. 18 Stabilizer Bar Replacement 1. Raise and support front of vehicle. 2. Remove nuts from both sides to disconnect linkage. Pull the bolts down through the retainers, grommets and spacers. These components will come free with the ends of the stabilizer. 3. Remove bracket-to-frame or body bolts, then the stabilizer bar, rubber bushings and brackets, Fig. 18. 4. Reverse procedure to install, noting the following: a. Install stabilizer bar insulators with the slit toward the front of the vehicle, stabilizer bar identification stamping appears on right side of vehicle and the offset in the bar is in the downward position. b. Position rubber bushings squarely in brackets with slit in bushings facing front of vehicle. c. Tighten stabilizer bar retaining nuts and bracket bolts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Stabilizer Bar, Sway Control > Component Information > Service and Repair > Front Suspension > Page 6074 Stabilizer Bar: Service and Repair Rear Suspension Fig. 9 Rear Stabilizer Assembly 1. Raise and support vehicle. 2. Remove the bolts and washers from the link brackets, Fig. 9. 3. Remove the nuts, washers and clamp from the anchor block studs. At this point, the stabilizer bar assembly will be clear from the vehicle. Proceed only if a new stabilizer bar will be installed. 4. Remove the insulator from the stabilizer bar. 5. Remove the upper link nuts, washers and bolts from the assembly. 6. Remove the link bracket from the link assembly. 7. Remove the link nuts, washers and bolts, then pry open lower link to obtain clearance from the link insulator. 8. Remove the link insulator from the stabilizer bar. 9. Reverse procedure to install. Tighten to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Spring ( Coil / Leaf ) > Component Information > Service and Repair > Coil Spring Replace Suspension Spring ( Coil / Leaf ): Service and Repair Coil Spring Replace Fig. 10 Coil Spring Removal Fig. 6 Coil Spring Installation 1. Raise and support vehicle so control arms hang free. 2. Remove two shock absorber nuts and push shock up through control arm and into spring. 3. Secure spring remover tool No. J-23028, or equivalent, to a suitable jack and position tool to cradle inner bushings, Fig. 5. 4. Remove stabilizer to lower control arm attachment. 5. Raise jack to relieve tension from lower control arm pivot bolts, then install a chain around spring and through control arm. 6. Remove attaching nuts and bolts, then slowly lower jack and control arm and remove spring. Do not apply force to lower control arm and ball joint to remove spring. Proper maneuvering of spring will allow for easy removal. 7. Reverse procedure to install. Refer to Figs. 5 and 6 for proper assembly of coil spring and pivot ball. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Spring ( Coil / Leaf ) > Component Information > Service and Repair > Coil Spring Replace > Page 6079 Suspension Spring ( Coil / Leaf ): Service and Repair Rear Suspension Leaf Spring Fig. 7 Single Leaf Spring Assembly SINGLE LEAF 1. Raise the vehicle and support at the frame rails. Support the rear axle separately to relieve the load on rear springs. 2. Remove shock absorbers, Fig. 7. 3. Remove the U-bolt and lower plate nuts, then the flat washers. On models equipped with a stabilizer bar, it will be necessary to remove the lower nuts, washers and anchor blocks, then swing the stabilizer bar down to obtain clearance. 4. Loosen but do not remove the shackle nuts. 5. Remove the anchor plate, then lower the axle away from the spring. Do not let the axle hang by the brake hose or damage may occur. 6. Remove the retainer nuts and washers, then the retainer. 7. Remove the spring-to-shackle nut, washers and bolt. 8. Remove the spring from vehicle. 9. Reverse procedure to install, noting the following: a. Tighten retainer nuts, U-bolt nuts and lower plate nuts to specifications. b. Adjust the rear suspension trim height by raising the rear axle until the top of the axle is 5.5-6.3 inches from the bottom of the frame. Damage to the spring and axle could result if the axle supports are not in complete contact with the axle and resting firmly on the floor. c. After trim height has been adjusted, tighten leaf spring rear anchor nuts and front anchor nuts to specifications. d. Install shock absorbers, then lower vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Spring ( Coil / Leaf ) > Component Information > Service and Repair > Coil Spring Replace > Page 6080 Fig. 8 Multi-leaf Spring Removal MULTIPLE LEAF 1. Raise and support vehicle. 2. Remove shock absorber. 3. Remove U-bolt and lower plate nuts and flat washers, Fig. 8. If equipped with a stabilizer shaft, it will be necessary to remove lower nuts, washers and anchor block. 4. Swing stabilizer shaft down to obtain clearance when lowering axle assembly. 5. Remove shackle nut and bolt. 6. Remove spring from rear shackle, Fig. 8. 7. Remove front hanger nut. 8. Remove spring from front hanger. 9. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Strut / Shock Absorber > Component Information > Technical Service Bulletins > Suspension - Shock Absorber/Strut Leakage Information Suspension Strut / Shock Absorber: Technical Service Bulletins Suspension - Shock Absorber/Strut Leakage Information INFORMATION Bulletin No.: 05-03-08-002C Date: October 16, 2009 Subject: Information on Replacement of Shock Absorbers and Struts Due to Fluid Leaks Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2010 model year and Inspection Procedures. Please discard Corporate Bulletin Number 05-03-08-002B (Section 03 - Suspension). This bulletin is intended to help identify the severity of shock absorber and strut fluid seepage. Improper diagnosis may lead to components being replaced that are within the manufacturer's specification. Shock absorbers and strut assemblies are fluid-filled components and will normally exhibit some seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorbers and struts are not to be replaced under warranty for seepage. Use the following information to determine if the condition is normal acceptable seepage or a defective component. Important Electronically controlled shock absorbers (MR) may have a tendency to attract dust to this oil film. Often this film and dust can be wiped off and will not return until similar mileage is accumulated again. Inspection Procedure Note The shock absorber or strut assembly DOES NOT have to be removed from the vehicle to perform the following inspection procedure. Use the following descriptions and graphics to determine the serviceability of the component. Shock Absorbers Do Not Replace shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom or top of the shock absorber and not originating from the shaft seal (the upper part of the lower shock tube). 2. Light film/residue on approximately 1/3 (a) or less of the lower shock tube (A) and originating from the shaft seal. Replace shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme wet film of oil covering more than 1/3 (b) of the lower shock tube and originating from the shaft seal. Coil-over Shock Absorber Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Strut / Shock Absorber > Component Information > Technical Service Bulletins > Suspension - Shock Absorber/Strut Leakage Information > Page 6085 Do Not Replace coil-over shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the lower shock absorber tube or the coil-over shock absorber components and not originating from the shaft seal (located at the top of the coil-over shock tube). 2. Light film/residue on the shock absorber tube, but not on the spring seat and originating from the shaft seal. Replace coil-over shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme, wet film of oil covering the shock absorber tube and pooling in the spring seat and originating from the shaft seal. Struts Do Not Replace Struts displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the strut tube or on other strut components and not originating from the shaft seal. 2. Light film/residue on the strut tube, but not on the spring seat and originating from the shaft seal. Replace Struts displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the strut tube and originating from the shaft seal (located at the top of the strut tube). 4. Extreme wet film of oil covering the strut tube and pooling in the spring seat and originating from the shaft seal. Correction Use the information published in SI for diagnosis and repair. Use the applicable published labor operation. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Strut / Shock Absorber > Component Information > Technical Service Bulletins > Suspension - Shock Absorber/Strut Leakage Information > Page 6086 Suspension Strut / Shock Absorber: Technical Service Bulletins Suspension - Shock Absorber/Strut Replacement Guidlines File In Section: Warranty Administration Bulletin No.: 72-05-12 Date: January, 1998 WARRANTY ADMINISTRATION Subject: Replacement of Shock Absorbers and Struts Labor Operations E3800, E3801, E3807, E5800, E5801, E5807, E3850, E3851, E3857, E5750, E5751, and E5757 Models: All Past, Present, and Future Passenger Cars & Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with enhanced service policies for the above listed subject labor operations. Service Management should make certain that all dealership personnel responsible for replacement of suspension components are familiar with GM Service Manual procedures. Effective with repair orders dated on or after January 15, 1998 the following must also be followed: - Shock absorber/strut assemblies are fluid filled components and will normally exhibit seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorber/strut assemblies are not to be replaced under warranty or seepage. - Defective shock absorber/strut assemblies will have a visible oil path or drip coming from the component. A visible oil path or drip coming from the shock absorber/strut assembly should be replaced as a defective component. - Only defective shock absorber/strut assemblies should be replaced. DO NOT replace pairs unless both are defective, unless otherwise instructed in the Service Manual and/or Service Bulletin. - Service Management approval is required on the repair order for replacement of struts or shocks in pairs. This approval includes noting the reason for replacement. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Strut / Shock Absorber > Component Information > Service and Repair > Front Suspension Suspension Strut / Shock Absorber: Service and Repair Front Suspension Fig. 7 Shock Absorber Replacement 1. Raise and support vehicle. 2. Hold shock upper stem from turning with a suitable wrench and remove nut, retainer and grommet. 3. Remove lower shock pivot bolts, then the shock absorber through the hole in the lower control arm, Fig. 7. 4. Reverse procedure to install. Tighten upper attaching nut and lower attaching bolts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Suspension Strut / Shock Absorber > Component Information > Service and Repair > Front Suspension > Page 6089 Suspension Strut / Shock Absorber: Service and Repair Rear Suspension Fig. 6 Shock Absorber Replacement 1. Raise vehicle and place jack stands under frame side rails. 2. Position a suitable jack under rear axle housing and raise slightly to support axle assembly. 3. Disconnect parking brake bracket from right shock absorber. 4. Disconnect shock absorber from upper mounting, Fig. 6. 5. Disconnect shock absorber from lower mounting, then remove from vehicle. 6. Reverse procedure to install. Tighten retaining nuts to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Bearing > Component Information > Adjustments Wheel Bearing: Adjustments Front Wheel Bearings 1. Raise and support front of vehicle. 2. While rotating wheel assembly in forward direction, tighten spindle nut to specifications to fully seat the bearings. 3. Back off spindle nut until just loose, then hand tighten spindle nut. 4. Loosen nut until hole in spindle aligns with a spindle nut slot, then install new cotter pin. 5. When properly adjusted, endplay should measure 0.001-0.005 inch. 6. Install rotor/hub cap, then lower vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Bearing > Component Information > Service and Repair > Front Wheel Bearing: Service and Repair Front Front Wheel Rotor/Hub Assembly 2WD Figure 5 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Bearing > Component Information > Service and Repair > Front > Page 6095 Figure 6 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Bearing > Component Information > Service and Repair > Front > Page 6096 Wheel Bearing: Service and Repair Rear Dana/Spicer Full Floating Axle REAR WHEEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Bearing & Cup REAR HUB AND/OR BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum REAR HUB AND/OR BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Bearing > Component Information > Service and Repair > Front > Page 6097 5. Pull hub and drum straight off axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Hub > Component Information > Service and Repair Wheel Hub: Service and Repair Front Wheel Rotor/Hub Assembly 2WD Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Suspension > Wheel Hub > Component Information > Service and Repair > Page 6101 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair Vehicle Lifting: Service and Repair Fig. 1 Tip-up Type Hoist Pad (front). Fig. 1 Tip-up Type Hoist Pad (front). Fig. 2 Tip-up Type Hoist Pad (rear). Fig. 2 Tip-up Type Hoist Pad (rear). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair > Page 6106 Fig. 3 Screw Type Hoist Pad (front). Fig. 3 Screw Type Hoist Pad (front). Fig. 4 Screw Type Hoist Pad (rear). Fig. 4 Screw Type Hoist Pad (rear). Fig. 5 Suspension Type Hoist (front). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair > Page 6107 Fig. 5 Suspension Type Hoist (front). Fig. 6 Suspension Type Hoist (rear). Fig. 6 Suspension Type Hoist (rear). Fig. 7 Floor Jack (front). Fig. 7 Floor Jack (front). Fig. 8 Floor Jack (rear). Fig. 8 Floor Jack (rear). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Vehicle Lifting > Component Information > Service and Repair > Page 6108 Fig. 9 Floor Jack (front frame). Fig. 9 Floor Jack (front frame). Fig. 10 Floor Jack (rear frame). Fig. 10 Floor Jack (rear frame). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires Tires: Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6113 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6114 Tires: Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6115 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6116 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6117 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6118 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6119 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6120 Tires: Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6121 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6122 Tires: Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 6123 Tires: Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: Customer Interest Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 6132 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 6133 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 6134 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: Customer Interest Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels > Page 6139 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 6145 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 6146 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 6147 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires Refinishing Aluminum Wheels > Page 6152 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 6157 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 6158 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: All Technical Service Bulletins Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 6163 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 6164 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 6165 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: All Technical Service Bulletins Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels > Page 6170 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 04-03-10-012B > Feb > 08 > Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-03-10-102 > Jun > 99 > Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 72-05-05 > Aug > 97 > Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing > Page 6187 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing > Page 6188 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing > Page 6189 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 6195 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 6196 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 6197 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires Refinishing Aluminum Wheels > Page 6202 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 6207 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 6208 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 04-03-10-012B > Feb > 08 > Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-03-10-102 > Jun > 99 > Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 72-05-05 > Aug > 97 > Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing > Page 6225 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing > Page 6226 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels Refinishing > Page 6227 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Bearing > Component Information > Adjustments Wheel Bearing: Adjustments Front Wheel Bearings 1. Raise and support front of vehicle. 2. While rotating wheel assembly in forward direction, tighten spindle nut to specifications to fully seat the bearings. 3. Back off spindle nut until just loose, then hand tighten spindle nut. 4. Loosen nut until hole in spindle aligns with a spindle nut slot, then install new cotter pin. 5. When properly adjusted, endplay should measure 0.001-0.005 inch. 6. Install rotor/hub cap, then lower vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front Wheel Bearing: Service and Repair Front Front Wheel Rotor/Hub Assembly 2WD Figure 5 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 6233 Figure 6 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 6234 Wheel Bearing: Service and Repair Rear Dana/Spicer Full Floating Axle REAR WHEEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Bearing & Cup REAR HUB AND/OR BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum REAR HUB AND/OR BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 6235 5. Pull hub and drum straight off axle housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Hub > Component Information > Service and Repair Wheel Hub: Service and Repair Front Wheel Rotor/Hub Assembly 2WD Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Hub > Component Information > Service and Repair > Page 6239 Remove or Disconnect 1. Brake caliper. 2. Dust cap (17) from the hub. 3. Cotter pin (16), nut (18) and washer (19). 4. Rotor/hub (21) from the spindle on the steering knuckle. Do not damage spindle threads. Outer wheel bearing (20) will come off the spindle with rotor/hub. The inner wheel bearing (22) remains inside the rotor/hub. Inspect 1. Rotor braking surfaces for scoring, pitting, or cracks. Repair or replace as necessary. 2. Wheel bearings and races. Install or Connect 1. Rotor/hub (21) on the spindle. Apply recommended high-temperature wheel bearing grease to the spindle and inside of rotor/hub before installing. 2. Outer wheel bearing (20) and washer (19). Apply a generous amount of the recommended high-temperature wheel bearing grease to the outer wheel bearing. 3. Nut (18). 4. Adjust wheel bearing. 5. Cotter pin (16). 6. Brake caliper. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Customer Interest for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: Customer Interest Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Customer Interest for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 6248 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: All Technical Service Bulletins Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels Plastic Wheel Nut Covers Loose/Missing > Page 6254 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Steering and Suspension > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Page 6255 Wheel Fastener: Specifications Wheel Nut Wheel Nut Wheel Lug Nuts 100 ft.lb Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Accumulator HVAC > Component Information > Locations Engine Compartment Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Actuator / Motor, HVAC > Component Information > Diagrams Schematic Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Actuator / Motor, HVAC > Component Information > Service and Repair > Air Inlet Actuator Replace Air Door Actuator / Motor: Service and Repair Air Inlet Actuator Replace NOTE: The air inlet valve vacuum actuators are located on the rear side of the heater/defroster case assembly. REMOVE OR DISCONNECT 1. Engine coolant. 2. Heater hoses. 3. Engine cover. 4. Vacuum connectors, as necessary. 5. Heater core. 6. Heater assembly screws and nuts. 7. Heater assembly. 8. Actuator linkage. 9. Actuator nuts. 10. Actuator(s). INSTALL OR CONNECT 1. Actuator(s). 2. Actuator nuts. 3. Actuator linkage. 4. Heater assembly. 5. Heater assembly screws and nuts. ^ Tighten screws to 6 N.m (53 lbs. in.). ^ Tighten nuts to 7.5 N.m (66 lbs. in.). 6. Heater core. 7. Vacuum connectors, as necessary. 6. Engine cover. 9. Heater hoses. 10. Engine coolant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Actuator / Motor, HVAC > Component Information > Service and Repair > Air Inlet Actuator Replace > Page 6266 Air Door Actuator / Motor: Service and Repair Mode Valve Actuator Replace NOTE: The mode valve vacuum actuator is located on the front of the heater/defroster case assembly. REMOVE OR DISCONNECT 1. Right floor air outlet. 2. Vacuum connectors, as necessary. 3. Actuator from the mounting bracket. 4. Actuator linkage from the actuator. INSTALL OR CONNECT 1. Actuator linkage to the actuator. 2. Actuator to the mounting bracket. 3. Vacuum connectors, as necessary. 4. Right floor air outlet. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Cable, HVAC > Component Information > Service and Repair > Defrost and Vent Control Cables Air Door Cable: Service and Repair Defrost and Vent Control Cables Temp, Defrost And Vent Cables REMOVE OR DISCONNECT 1. Engine cover. 2. Instrument panel lower filler. 3. Control assembly. 4. Defroster control cable from the control assembly. 5. Control cable retainer screw. 6. Defroster control cable from the heater module. 7. Control cable retainer screw. 8. Vent control cable from the control assembly. 9. Vent control cable from the heater module. INSTALL OR CONNECT 1. Vent control cable to the heater module. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Cable, HVAC > Component Information > Service and Repair > Defrost and Vent Control Cables > Page 6271 2. Vent control cable to the control assembly. 3. Control cable retainer screw. ^ Tighten screw to 1.4 N.m (12 lbs. in.). 4. Defroster control cable to the heater module. 5. Control cable retainer screw. ^ Tighten screw to 1.4 N.m (12 lbs. in.). 6. Defroster control cable to the control assembly. 7. Control assembly. 8. Instrument panel lower filler. 9. Engine cover. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Cable, HVAC > Component Information > Service and Repair > Defrost and Vent Control Cables > Page 6272 Air Door Cable: Service and Repair Temperature Cable Temperature Control Cable REMOVE OR DISCONNECT 1. Engine cover. 2. Instrument panel lower filler. 3. Control assembly. Refer to Control Assembly. See: Control Assembly/Service and Repair 4. Retainer. 5. Temperature control cable from the control assembly. 6. Temperature control cable from the heater assembly. INSTALL OR CONNECT 1. Temperature control cable to the heater assembly. 2. Temperature control cable to the control assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Air Door, HVAC > Air Door Cable, HVAC > Component Information > Service and Repair > Defrost and Vent Control Cables > Page 6273 3. Retainer. 4. Control assembly. Refer to Control Assembly. See: Control Assembly/Service and Repair 5. Instrument panel lower filler. 6. Engine cover. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates Blower Motor: Customer Interest A/C - Odor at Start up in Humid Climates File In Section: 1 - HVAC Bulletin No.: 53-12-12A Date: December, 1996 Subject: Air Conditioning Odor at Start Up in Humid Climates (Disinfect Evaporator Core, Install Delayed Blower Control Package) Models: 1993-96 Passenger Cars (Except GEO) 1993-96 Light Duty Models (Except Tracker) This bulletin is being revised to update the wiring diagrams, add the Corvette (with RPO C60) and delete medium/heavy duty trucks. Please discard Corporate Bulletin Number 53-12-12 (Section 1 HVAC). Condition Some owners may comment on odors emitted from the air conditioning system, primarily at start up in hot, humid climates. Cause This odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. Correction To remove odors of this type, it is necessary to eliminate the microbial growth and prevent its recurrence. To accomplish this, these two procedures must be completed. ^ Deodorize the evaporator core using Deodorizing Aerosol Kit, P/N 12377951 (AC Delco 15-102). ^ Install the new A/C Delayed Blower Control Package, P/N 12370470, (AC Delco 15-8632). The blower control package will enable the blower to run at high speed for five (5) minutes. It will do so approximately fifty (50) minutes after the ignition has been turned off if the compressor had been engaged for four (4) or more minutes prior to shutting off engine. By doing so, the evaporator case and core are dried out, reducing the chances of a recurring A/C odor. Procedure 1. Visually inspect the air conditioning evaporator drain hose for obstructions or working condition. 2. Apply deodorizing aerosol as described in the instructions supplied with the kit. Once the deodorizer has been applied, some of the mixture may overflow from the drain hose. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6282 3. The chart identifies specific instructions for each vehicle. This chart will identify the proper deodorizing procedure, template and wiring diagram. Deodorizing the evaporator case can easily be done by removing the blower motor resistor and tape off opening. The nozzle can now be inserted through a pierced hole in the tape to deodorize the evaporator case. For some of the vehicles specified below, a drilling procedure is identified in the deodorizing instructions. This type of alternative procedure and others can be done by using the referenced templates in the chart. 4. Complete detailed installation instructions are supplied with the blower control package. Important: A. 1996 ONLY (Use blower resistor location for drilling procedure) B. 1994-1996 ONLY Refer to appropriate Service Manual for enabling afterblow feature through on-board diagnostics. Parts Information Parts are currently available from GMSPO. Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6283 For vehicles repaired under warranty, use as shown. Figure 1 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6284 Figure 2 Figure 3 Figure 4 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6285 Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6286 Figure 7 Figure 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6287 Figure 9 Figure 10 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6288 Figure 11 Figure 12 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6289 Figure 13 Figure 14 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6290 Figure 15 Figure 16 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6291 Figure 17 Figure 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6292 Figure 19 Figure 20 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6293 Figure 21 Figure 22 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6294 Figure 23 Figure 24 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6295 Figure 25 Figure 26 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6296 Figure 27 Figure 28 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 461103 > Dec > 94 > HVAC Fan - Inoperative in One or More of the Four Speeds Blower Motor: Customer Interest HVAC Fan - Inoperative in One or More of the Four Speeds File In Section: 1 - HVAC Bulletin No.: 46-11-03 Date: December, 1994 Subject: HVAC Fan Inoperative in One or More of the Four Speeds (Replace Blower Relay and Connector) Models: 1992-94 Chevrolet and GMC Truck M/L Vans with Air Conditioner (RPO C60) Condition Some owners of the above listed models may experience one or more of the four speeds of the fan to be inoperative. Cause High blower relay inoperative. Correction Replace connector and high blower relay with service kit using the following procedure: 1. Prep the vehicle. Be certain the negative ground cable is disconnected from the battery. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 461103 > Dec > 94 > HVAC Fan - Inoperative in One or More of the Four Speeds > Page 6301 2. Remove the relay from the multi-use bracket. See Figure 1, View A. 3. Unwrap tape from the harness from relay back to major conduit. 4. Cut harness wires at base of original connector. This will provide maximum wire length for splices. 5. Using crimp connectors included in service kit (P/N 12166225 Blower Relay Service Kit), splice leads from numbered cavities on new connector to color coded leads from original harness as follows: 6. Splice lead from cavity 30 to purple lead. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > Customer Interest for Blower Motor: > 461103 > Dec > 94 > HVAC Fan - Inoperative in One or More of the Four Speeds > Page 6302 7. Splice lead from cavity 86 to black lead approximately 1 inch further from connector than the first splice. 8. Splice lead from cavity 87 to red lead. 9. Splice lead from cavity 87A to dark blue lead. 10. Splice lead from cavity 85 to orange lead. 11. Fasten new relay (P/N 12077864 A/C Blower Relay) to newly spliced connector. 12. Reconnect negative cable to battery. 13. Test fan lever to verify there are four blower fan speeds. Re-check splices as needed. 14. Heat shrink each end of the five crimp connectors Caution: Care must be taken not to touch heat shrink wrap while still hot. 15. Harness all five spliced wires together with electrical tape from new connector back to major conduit. 16. Fasten new relay to multi-use bracket. Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates Blower Motor: All Technical Service Bulletins A/C - Odor at Start up in Humid Climates File In Section: 1 - HVAC Bulletin No.: 53-12-12A Date: December, 1996 Subject: Air Conditioning Odor at Start Up in Humid Climates (Disinfect Evaporator Core, Install Delayed Blower Control Package) Models: 1993-96 Passenger Cars (Except GEO) 1993-96 Light Duty Models (Except Tracker) This bulletin is being revised to update the wiring diagrams, add the Corvette (with RPO C60) and delete medium/heavy duty trucks. Please discard Corporate Bulletin Number 53-12-12 (Section 1 HVAC). Condition Some owners may comment on odors emitted from the air conditioning system, primarily at start up in hot, humid climates. Cause This odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. Correction To remove odors of this type, it is necessary to eliminate the microbial growth and prevent its recurrence. To accomplish this, these two procedures must be completed. ^ Deodorize the evaporator core using Deodorizing Aerosol Kit, P/N 12377951 (AC Delco 15-102). ^ Install the new A/C Delayed Blower Control Package, P/N 12370470, (AC Delco 15-8632). The blower control package will enable the blower to run at high speed for five (5) minutes. It will do so approximately fifty (50) minutes after the ignition has been turned off if the compressor had been engaged for four (4) or more minutes prior to shutting off engine. By doing so, the evaporator case and core are dried out, reducing the chances of a recurring A/C odor. Procedure 1. Visually inspect the air conditioning evaporator drain hose for obstructions or working condition. 2. Apply deodorizing aerosol as described in the instructions supplied with the kit. Once the deodorizer has been applied, some of the mixture may overflow from the drain hose. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6308 3. The chart identifies specific instructions for each vehicle. This chart will identify the proper deodorizing procedure, template and wiring diagram. Deodorizing the evaporator case can easily be done by removing the blower motor resistor and tape off opening. The nozzle can now be inserted through a pierced hole in the tape to deodorize the evaporator case. For some of the vehicles specified below, a drilling procedure is identified in the deodorizing instructions. This type of alternative procedure and others can be done by using the referenced templates in the chart. 4. Complete detailed installation instructions are supplied with the blower control package. Important: A. 1996 ONLY (Use blower resistor location for drilling procedure) B. 1994-1996 ONLY Refer to appropriate Service Manual for enabling afterblow feature through on-board diagnostics. Parts Information Parts are currently available from GMSPO. Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6309 For vehicles repaired under warranty, use as shown. Figure 1 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6310 Figure 2 Figure 3 Figure 4 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6311 Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6312 Figure 7 Figure 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6313 Figure 9 Figure 10 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6314 Figure 11 Figure 12 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6315 Figure 13 Figure 14 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6316 Figure 15 Figure 16 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6317 Figure 17 Figure 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6318 Figure 19 Figure 20 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6319 Figure 21 Figure 22 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6320 Figure 23 Figure 24 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6321 Figure 25 Figure 26 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6322 Figure 27 Figure 28 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 461103 > Dec > 94 > HVAC Fan - Inoperative in One or More of the Four Speeds Blower Motor: All Technical Service Bulletins HVAC Fan - Inoperative in One or More of the Four Speeds File In Section: 1 - HVAC Bulletin No.: 46-11-03 Date: December, 1994 Subject: HVAC Fan Inoperative in One or More of the Four Speeds (Replace Blower Relay and Connector) Models: 1992-94 Chevrolet and GMC Truck M/L Vans with Air Conditioner (RPO C60) Condition Some owners of the above listed models may experience one or more of the four speeds of the fan to be inoperative. Cause High blower relay inoperative. Correction Replace connector and high blower relay with service kit using the following procedure: 1. Prep the vehicle. Be certain the negative ground cable is disconnected from the battery. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 461103 > Dec > 94 > HVAC Fan - Inoperative in One or More of the Four Speeds > Page 6327 2. Remove the relay from the multi-use bracket. See Figure 1, View A. 3. Unwrap tape from the harness from relay back to major conduit. 4. Cut harness wires at base of original connector. This will provide maximum wire length for splices. 5. Using crimp connectors included in service kit (P/N 12166225 Blower Relay Service Kit), splice leads from numbered cavities on new connector to color coded leads from original harness as follows: 6. Splice lead from cavity 30 to purple lead. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Blower Motor: > 461103 > Dec > 94 > HVAC Fan - Inoperative in One or More of the Four Speeds > Page 6328 7. Splice lead from cavity 86 to black lead approximately 1 inch further from connector than the first splice. 8. Splice lead from cavity 87 to red lead. 9. Splice lead from cavity 87A to dark blue lead. 10. Splice lead from cavity 85 to orange lead. 11. Fasten new relay (P/N 12077864 A/C Blower Relay) to newly spliced connector. 12. Reconnect negative cable to battery. 13. Test fan lever to verify there are four blower fan speeds. Re-check splices as needed. 14. Heat shrink each end of the five crimp connectors Caution: Care must be taken not to touch heat shrink wrap while still hot. 15. Harness all five spliced wires together with electrical tape from new connector back to major conduit. 16. Fasten new relay to multi-use bracket. Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Locations > Auxiliary A/C Blower Motor Assembly Auxiliary A/C Blower Motor And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Locations > Auxiliary A/C Blower Motor Assembly > Page 6331 Auxiliary Heater Blower Motor And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Locations > Auxiliary A/C Blower Motor Assembly > Page 6332 Engine Compartment Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Diagrams > Front Blower Motor Blower Motor: Diagrams Front Blower Motor C424, Blower Motor C425, Blower Motor C150, Blower Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Diagrams > Front Blower Motor > Page 6335 C424, Auxiliary A/C Blower Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Diagrams > Front Blower Motor > Page 6336 C421, Auxiliary Heater Blower Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Service and Repair > With Air Conditioning Blower Motor: Service and Repair With Air Conditioning Front Accumulator Case Figure 32-Nut and Fan Removal REMOVE OR DISCONNECT 1. Negative battery cable. 2. Windshield washer fluid bottle. 3. Electrical connections. 4. Blower motor flange screws. 5. Nut from the blower motor. 6. Fan from the blower motor. 7. Spacer. 8. Blower motor. INSTALL OR CONNECT 1. Blower Motor. 2. Space. 3. Fan to the blower motor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Service and Repair > With Air Conditioning > Page 6339 4. Nut to the blower motor. 5. Blower motor flange screws. 6. Electrical connections. 7. Windshield washer fluid bottle. 8. Negative battery cable. Rear Figure 41-Cover Removal Figure 42-Rear Wiring Harness REMOVE OR DISCONNECT 1. Negative battery cable. 2. Storage box. 3. Cover. 4. Electrical connections. 5. Blower motor flange screws. 6. Blower motor. INSTALL OR CONNECT 1. Blower motor. 2. Blower motor flange screws. 3. Electrical connections. 4. Cover. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Service and Repair > With Air Conditioning > Page 6340 5. Storage box. 5. Cover assembly. 6. Negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Service and Repair > With Air Conditioning > Page 6341 Blower Motor: Service and Repair Without Air Conditioning Front Blower Motor And Case REMOVE OR DISCONNECT 1. Electrical connector from blower motor. 2. Coolant recovery reservoir. 3. Windshield washer fluid container. 4. Blower motor flange screws. 5. Cooling tube. 6. Blower motor. 7. Blower motor fan. INSPECT ^ Blower motor terminals for corrosion. Clean corrosion from the terminals or replace the blower motor as necessary. ^ Flange of the blower motor for damage or distortion that could cause an air leak. Repair as necessary. ^ Blower fan for damage and distortion. Repair or replace as necessary. INSTALL OR CONNECT 1. Blower motor fan. 2. Blower motor. 3. Cooling tube. 4. Blower motor flange screws. 5. Windshield washer fluid container. 6. Coolant recovery reservoir. 7. Electrical connector to blower motor. ^ Check circuit operation. Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Service and Repair > With Air Conditioning > Page 6342 Figure 20-Rear Heater Component View Figure 21-Heater Wiring-Resistor Replacement REMOVE OR DISCONNECT 1. Negative battery cable. 2. Screws. 3. Cover. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor > Component Information > Service and Repair > With Air Conditioning > Page 6343 4. Wire connector from the ground terminal. 5. Blower motor connector. 6. Blower motor flange screws. 7. Blower motor. 8. Nut. 9. Fan from the blower motor. INSTALL OR CONNECT 1. Fan to the blower motor. 2. Nut. 3. Blower motor. 4. Blower motor flange screws. 5. Blower motor connector. 6. Wire to the ground terminal. 7. Cover. 8. Screws. 9. Negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Relay > Component Information > Locations Blower Motor Relay: Locations Image updated by TSB 461103 Dated December 1994 Located on multi use bracket, at RH side of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Relay > Component Information > Locations > Page 6347 C164, HI A/C Blower Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Resistor > Component Information > Locations > Blower Resistor Engine Compartment Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Resistor > Component Information > Locations > Blower Resistor > Page 6352 Blower Motor Resistor: Locations With Air Conditioning Blower Resistor Rear A/C Wiring Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Resistor > Component Information > Locations > Blower Resistor > Page 6353 Blower Motor Resistor: Locations Without Air Conditioning Blower Motor Resistor Figure 21-Heater Wiring-Resistor Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Resistor > Component Information > Diagrams > Heater Blower Resistor C151, Heater Blower Resistor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Resistor > Component Information > Diagrams > Heater Blower Resistor > Page 6356 C160, Blower Resistor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Locations Blower Motor Switch: Locations Air Conditioning, Heater Control I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Locations > Page 6360 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Locations > Page 6361 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch C261, Auxiliary A/C Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 6364 C243, Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 6365 C243, Heater Blower Control Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 6366 C243, Heater Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Specifications > With HD6/HR6-HE Compressor Compressor Clutch: Specifications With HD6/HR6-HE Compressor Clutch Plate & Rotor .............................................................................................................................................................. 0.50-0.76mm (0.020-0.030") Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Specifications > With HD6/HR6-HE Compressor > Page 6372 Compressor Clutch: Specifications With HR100/HR110-MD Compressor Clutch Air Gap ..................................................................................................................................... ...................................... 0.5-7.6mm (0.020-0.030") Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Specifications > With HD6/HR6-HE Compressor > Page 6373 Compressor Clutch: Specifications With SD-7H15 Compressor Clutch Air Gap ........................................................................................................................................................ 0.49 to 0.79 mm (0.016 to 0.031 inch) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Specifications > With HD6/HR6-HE Compressor > Page 6374 Compressor Clutch: Specifications With V5 Compressor Clutch Air Gap ..................................................................................................................................... .................................. 0.50-0.076mm (0.20-0.030") Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor Compressor Clutch: Service and Repair With HR100/HR110-MD Compressor Clutch Plate and Hub Assembly Remove or Disconnect 1. If compressor is on the vehicle, loosen compressor mounting brackets, disconnect the compressor drive belt and reposition the compressor for access, if necessary. Compressor In Holding Fixture If compressor has been removed from the vehicle, attach the compressor to Holding Fixture J 25008-A and clamp the Holding Fixture in a vise. ^ Compressor mounting holes are metric. Use proper metric bolts with holding fixture J 25008-A. Clutch Plate & Hub Assembly Removal 2. Thread the Clutch Plate and Hub Assembly Remover J 33013-B, into the hub. Hold the body of the Remover with a wrench and turn the center screw into the Remover body to remove the Clutch Plate and Hub assembly. 3. Remove the shaft key. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6377 Installing Shaft Key 1. Install the shaft key into the hub key groove. Allow the key to project approximately 4.8mm (3/16") out of the keyway. The shaft key is curved slightly to provide an interference lit in the shaft key groove of the hub. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the Clutch Plate and Hub assembly. 3. Align the shaft key with the shaft keyway and place the Clutch Plate and Hub assembly onto the compressor shaft. NOTICE: To avoid internal damage to the compressor, do not drive or pound on the clutch hub or shaft. Installing Clutch Plate & Hub Assembly 4. Install the Clutch Plate and Hub Installer J 9401-B as illustrated. 5. Hold the hex portion of the Installer Body J 9401-B with a wrench and tighten the center screw to press the hub onto the shaft until there is a 0.5-7.6mm (0.020-0.030") air gap between the frictional surfaces of the clutch plate and clutch rotor. 6. If operation is performed with compressor on vehicle, connect drive belt, tighten mounting brackets and adjust belt tension. 4-Pole Clutch 1. Remove the Clutch Plate and Hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6378 Removing Rotor & Bearing Assembly Retaining Ring 2. Remove Rotor and Bearing assembly retaining ring, using Snap Ring Pliers J 6083. Mark the location of the clutch coil terminals. If only the Clutch Rotor and/or Rotor Bearing are to be replaced, bend the screw head washer away from the pulley rim and remove the six (6) mounting screws before proceeding with Step 3. Discard the mounting screws. Removing Clutch Rotor Assembly 3. Install Rotor and Bearing Puller J 25031 down into the rotor until the Puller arms engage the recessed edge of the rotor hub. Hold the Puller and arms in place and tighten the Puller screw against the Puller Guide to remove the Clutch Rotor and Bearing assembly, being careful not to drop the Puller Guide. 4. If the pulley rim mounting screws were removed in Step 2, only the Clutch Rotor and Bearing assembly will be removed for replacement. The Clutch Coil and Housing assembly is pressed onto the Front Head of the compressor with a press fit and will not be removed unless the pulley rim mounting screws are left securely in place and the pulley rim pulls the Coil and Housing assembly off with the total Clutch Rotor and Pulley Rim Assembly. Clutch Rotor Bearing Removal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6379 5. Place the Rotor and Bearing assembly on blocks as shown in the illustration. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A. Rotor And Bearing Assembly It is not necessary to remove the staking at the rear of the rotor hub to remove the bearing. However, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore, or the bearing may be damaged. Install or Connect 1. Place the Rotor and Hub assembly face down on a clean. flat and firm surface. Installing Clutch Rotor Bearing 2. Align the new bearing squarely with the hub bore and using Pulley and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into the hub. The Installer will apply force to the outer race of the bearing if used as shown. 3. Using a center punch with a 45° angle point, stake 1.1-1.4mm (0.045-0.055" deep) the bearing in three places 120° apart as shown, but do not stake too deeply to avoid distorting the outer race of the bearing. 4. Replace rotor and bearing assembly. On-Vehicle A. Position the Rotor and Bearing assembly on the front head. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6380 Rotor And Bearing Assembly B. With Rotor & Bearing Installer J 26271-A (without driver handle) in position and Rotor and Bearing assembly aligned with the Front Head as shown in the illustration, drive the assembly part way onto the head. C. Plug clutch coil connector onto Clutch Coil. D. Position the Clutch Coil so the three (3) locating tabs will align with the holes in the head and continue to drive the Rotor and Bearing assembly onto the front head. E. Install the retainer ring. F. Reassemble the Clutch Plate and Hub with the shaft key onto the shaft with Installer J 9401-B until 0.5-7.6mm (0.020-0.030") air gap is obtained. G. Install shaft lock nut. Torque to 14 N.m (10 lb.ft.). On-Bench Installing Rotor & Bearing Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6381 Reassemble the Rotor and Bearing assembly to the front head of the compressor using Rotor & Bearing Installer J 26271-A. With Installer assembled to the Universal Handle J 29886, as shown in the illustration, force will be applied to the inner race of the bearing and the face of the rotor when installing the assembly onto the front head of the compressor. 5. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083. 6. Apply sealer include GM 12345382 (Loctite 242 or equivalent) to threads of pulley rim mounting screws. Install screws but do not torque the screws. 7. Rotate the pulley rim and rotor 10 insure that pulley rim is rotating "in-line". If pulley rim is distorted (does not rotate in-line), adjust or replace pulley rim. 8. Tighten pulley rim mounting screws to 11 N.m (100 in. lbs.) torque and lock screw heads in place by bending screw head washer similar to original crimp. 9. Reinstall Clutch Plate and Hub assembly. 6-Pole Clutch 1. Remove the clutch plate and hub assembly as described previously. Removing Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring, using Snap Ring Pliers J 6083. Removing Clutch Rotor Assembly - Poly-Groove Drive Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6382 Pulley Rotor & Bearing Puller Installation 3. Install Pulley Rotor and Puller Guide J 25031 to the front head, and install J 33020 Pulley Rotor and Bearing Puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. Pulley Rotor & Bearing Puller Removal 4. Hold the J 33020 Puller in place and tighten the puller screw against the Puller Guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal, the rotor hub must be properly supported. Bearing Assembly Remove the forcing screw from J 33020 Puller and with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in the illustration. 6. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A and J 29886 Universal Handle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6383 Pulley Rotor & Bearing Puller Removal It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Bearing Assembly 1. Place the Pulley Rotor on the J 21352-A Support Block to fully support the rotor hub during bearing installation. Do not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using Puller and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into hub. The Installer will apply force to the outer race of the bearing if used as shown. Bearing Staking 3. Place Bearing Staking Guide J 33019-1 and Bearing Staking Pin J 33019-2 in the hub bore as shown in the illustration. Shift the rotor and bearing assembly on the J 21352-A Support Block to give full support of the hub under the staking pin location. A heavy duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide alter each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching, the bearing. Stake three (3) places 120° apart as shown. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6384 NOTICE: The stake metal should not contact the outer race of the bearing to prevent the possibility of distorting the outer race. Bearing Staked In Place 5. With the compressor mounted to the J 25008-A Holding Fixture, position the Rotor and Bearing Assembly on the front head. Using Rotor and Bearing Installer J 9481-A and Universal Handle J 29886 drive the rotor and bearing assembly onto the front head. With the Installer assembled to the Handle as shown in the illustration. force will be applied to the inner race of the bearing when installing the assembly onto the front head of the compressor. Pulley Rotor And Bearing Assembly 6. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083. 7. Reinstall clutch plate and hub assembly as described previously. Clutch Coil and/or Pulley Rim CLUTCH COIL AND PULLEY RIM INSTALLATION AND REMOVAL PROCEDURES FOR THE 6 POLE CLUTCH ARE THE SAME AS THE 4 POLE EXCEPT STEPS 1 THROUGH 4 OF THE CLUTCH ROTOR AND/OR BEARING - 6 POLE CLUTCH, REMOVAL OR DISCONNECT MUST BE USED. V-Groove Drive - 4 Pole Clutch Remove or Disconnect 1. Perform Steps 1 through 4 of COMPRESSOR CLUTCH ROTOR AND/OR BEARING removal procedure but do not loosen or remove the pulley rim mounting screws until the Clutch Rotor, Coil and Pulley Rim assembly have been removed from the Front Head. Be careful not to drop the Puller Guide J 25031 when removing the assembly. 2. Remove the pulley rim mounting screws and discard. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6385 Clutch Coil Assembly 3. Slide the pulley rim off the Rotor and Hub assembly The Pulley Rim and the Clutch Coil) are replaceable at this point. Install or Connect Assembling Clutch Coil, Pulley Rim, Rotor & Bearing 1. Assemble the Clutch Coil, Pulley Rim and the Clutch Rotor and Bearing assembly as shown in the illustration. Use new screws and apply sealer GM 12345382 (Loctite 242, or equivalent) to screw threads but do not lock the screws in place. Installing Rotor And Bearing Assembly (On-Vehicle) 2. Place the assembly on the neck of the Front Head and seat into place using Rotor & Bearing Installer J 26271-A. Before fully seating the assembly on the Front Head, be sure the clutch coil terminals are in the proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil align with the locator holes in the Front Head. 3. Install the rotor and bearing assembly retaining ring and reassemble the Clutch Plate and Hub assembly as described in "Compressor Clutch Plate and Hub Assembly" Replacement procedure. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.6mm (0.020-0.030"). Rotate the Pulley Rim and Rotor to be sure the Pulley Rim is rotating "in-line" and adjust or replace as required. 4. Tighten the pulley rim mounting screws to 11 N.m (100 in. lbs.) torque and lock the screw heads in place by bending screw head washer, similar to original crimp and lock bends on washers. Poly-Groove Drive Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6386 2. Remove the pulley rotor and bearing assembly as described previously. Mark the location of the clutch coil terminals on the compressor. Removing Poly-Groove Clutch Coil Removing Poly-Groove Clutch Coil (Optional Method) 3. Install Rotor and Bearing Puller Guide J 25031 to the front head and install Puller J 8433 with Poly-V-Belt Puller Leg Set J 24092 and remove the clutch coil from the front head. Clutch coil may also be removed by using rotor and bearing puller guide J 25031 with puller tool J 25287. Install or Connect 1. Place the clutch coil assembly on the neck of the front head with clutch coil terminals in line with mark described in Step 2 of the removal procedure. 2. Place the pulley rotor and bearing assembly on the neck of the front head and seat the clutch coil and pulley rotor in place using Rotor and Bearing Installer J 26271-A. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6387 Before fully seating the assembly on the front head. be sure the clutch coil terminals are in proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil housing align with the located holes in the front head. 3. Install the pulley-rotor and bearing assembly retaining ring and reassemble the clutch plate and hub assembly as described in Clutch Plate and Hub Assembly-Replace 4. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.0mm (0.020-0.030"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6388 Compressor Clutch: Service and Repair With V5 Compressor Clutch Plate and Hub Assembly Remove or Disconnect Removing Shaft Nut 1. Clamp the holding fixture J 34992 in a vise and attach compressor to holding fixture with thumb screws J 34992-1. 2. Keep the clutch hub and drive plate assembly from turning by using the clutch hub holding tool J 33027-A. Remove the shaft nut using shaft nut socket J 33022. Clutch Plate And Hub Assembly Removal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6389 3. Thread the Clutch Plate and Hub Assembly Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. 4. Remove the shaft key and retain for reassembly. Install or Connect Shaft Key, Clutch Plate/Hub Installation 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2 mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interference fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assembly. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor shaft. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to compressor may result. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6390 Installing Clutch Plate & Hub Assembly 4. Remove the J 33013-B remover-installer center screw and reverse the body direction on the center screw as shown in the illustration. 5. Install the clutch plate and hub installer J 33013-B with bearing as shown in the illustration. The body of the J 33013-B installer should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer J 33013-B body to press the hub onto the shaft. Tighten the body several turns, remove the installer and check to see that the shaft key is still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.5-0.076mm (0.20-0.030"). ^ If the center screw is threaded fully onto the end of the compressor shaft, or if the body of the installer is held and the center screw is rotated, the key will assume the position as shown in the illustration and will break the clutch hub. 7. Remove installer J 33013-B. check for proper positioning of the shaft key (even or slightly above the clutch hub). Install the shaft nut. Hold the clutch plate and hub assembly with clutch hub holding tool J 33027-A and using shaft nut socket J 33022, tighten the nut against the crankshaft shoulder to 16.5 N.m (12 lbs.ft.) torque, using a 17.5 N.m (12.5 lbs.ft.) torque wrench. 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Clutch Rotor and/or Bearing Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6391 Removing Pulley Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring. using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6392 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide J 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. 4. Hold the J 33020 puller in place and tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and, with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in the illustration. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398-A and J 29886 universal handle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6393 It is not necessary to remove the staking in front of the bearing to remove the bearing, however , it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: Do Not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle 1 29886, drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing if used as shown. Staking Bearing In Rotor Hub Bore 3. Place bearing staking guide J 33019-1 and bearing staking pin 133019 in the hub bore as shown in Figure 13. Shift the rotor and bearing assembly on the J 21352-A support block to give full support of the hub under the staking pin location. A heavy-duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to but not touching the bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6394 Bearing Staked In Place The stake metal should not contact the outer face of the bearing to prevent the possibility of distorting the outer race. Stake three (3) places 120° apart as shown in the illustration. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 34992 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley rotor and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 34992-2 through bolts and washers through the puller bar slots and thread them into the J 34992 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in-line contact with the inner face of the bearing, loosen the J 8433-3 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly as described previously. Clutch Coil Remove or Disconnect 1. Perform Steps 1 through 4 of "Clutch Rotor and/or Bearings" removal procedure. Mark clutch coil terminal location on compressor front head. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6395 Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs as shown in the illustration. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. Place the clutch coil assembly on the front head with the terminals positioned at the "marked location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. 3. Center the J 8433-1 puller crossbar in the countersunk center hole of the J 33024 clutch coil installer. Install the J 34992-2 through bolts and washers through the crossbar slots and thread them, into the holding fixture J 34992 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay "in-line" during installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6396 Installing Clutch Coil Assembly 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three (3) places 120° apart. to ensure clutch coil remaining in position. Staking Clutch Coil To Front Head ^ Stake size should be only one half the area of the punch tip and only approximately 0.28-0.35mm (0.01-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly according as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6397 Compressor Clutch: Service and Repair With HD6/HR6-HE Compressor Clutch Plate and Hub Assembly Remove or Disconnect Clutch Plate And Hub Assembly Removal 1. Clamp the holding fixture J 33020 in a vise and attach compressor to holding fixture with thumb screws J 33026-1. 2. With center screw forcing tip in place to thrust against the end of the shaft, thread the Clutch Plate and Hub Assembly installer-Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to the compressor may result. The forcing tip on J 33013-B remover-installer screw must be flat or the end of the shaft/axial plate assembly will be damaged. 3. Remove the shaft key and retain for assembly. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6398 Shaft Key, Clutch Plate/Hub Installation 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interferance fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assemblies. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor Installing Clutch Plate & Hub Assembly 4. Remove the forcing tip on J 33013-B clutch plate and hub assembly installer-remover center screw and reverse the body direction on the center Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6399 screw. Removing Pulley Rotor And Bearing Assembly 5. Install the clutch plate and hub installer-remover J 33013-B with bearing. The body of the J 33013-B installer-remover should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer-remover J 33013-B body to press the hub onto the shaft. Tighten the body several turns, remove the installer and check to see that the shaft key is still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.50-0.76mm (0.020-0.030"). NOTICE: If the center screw is threaded fully onto the end of the compressor shaft, or if the body of the installer is held and the center screw is rotated, the key will wedge and will break the clutch hub. 7. Remove installer J 33013-B, check for proper positioning of the shaft key (even or slightly above the clutch hub). 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Clutch Rotor and/or Bearing Remove or Disconnect 1. Remove the clutch plate and hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6400 Installing-Removing Pulley Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring, using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6401 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide J 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots in the rotor. 4. Hold the J 33020 puller in place and tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398A and J 29886 universal handle. NOTICE: It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will he necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6402 Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: DO NOT support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle J 29886 drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing. Staking Bearing In Rotor Hub Bore 3. Place bearing staking guide J 33019-1 and bearing staking pin J 33019-2 in the hub bore. Shift the rotor and bearing assembly on the J 21352-A support block to give full support of the hub under the staking pin location. A heavy-duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury strike the staking pin with a hammer until a metal stake similar to the original is formed down to but not touching the bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6403 Bearing Staked In Place Noisy bearing operation and reduced bearing life may result if outer bearing race is deformed while staking, the stake metal should not contact the outer race of the bearing. Stake three places 120° apart. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 33026 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley, rotor, and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 33026-2 through bolts and washers through the puller bar slots and thread them into the J 33026 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in line contact with the inner race of the bearing, loosen the J 8433-1 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly. Clutch Coil Remove or Disconnect 1. Perform Steps 1 through 4 of Clutch Rotor and/or Bearing removal procedure. Mark clutch coil terminal location on compressor front head. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6404 Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. Place the clutch coil assembly on the front head with the terminals positioned at the "marked" location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6405 Installing Clutch Coil Assembly 3. Center the J 8433-1 puller crossbar in the counter-sunk center hole of the J 33024 clutch coil installer. Install the J 33026-2 through bolts and washers through the crossbar slots and thread them into the holding fixture J 33026 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay in-line during installation. Staking Clutch Coil To Front Head 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three places 120° apart, to ensure clutch coil remains in position. Details Of Stakes In Front Head For Clutch Coil ^ Stake size should be only one-half the area of the punch tip and be only approximately 0.28-0.35mm (0.010-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6406 Compressor Clutch: Service and Repair With SD-7H15 Compressor Disassemble Remove or Disconnect Tools Required: J 6435 External Snap Ring Pliers J 8433 Puller Set J 37825 Puller Plate Assembly J 37827 Puller Pilot J 37828 Puller Fingers J 37872 Spanner Wrench Removing The Nut ^ Insert the two pins of the J 37872 into any two threaded holes of the clutch front plate. Hold the clutch plate stationary. 1. Hex nut using a 14 mm socket. Removing The Clutch Plate 2. Clutch front plate using J 37825. ^ Align the puller center bolt to the compressor shaft. ^ Thumb tighten the three puller bolts into the threaded holes. ^ Turn the center bolt to the right with the socket wrench until the front plate is loosened. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6407 Removing The Internal Snap Ring 3. External front housing snap ring with J 6435. 4. Rotor pulley assembly. ^ Insert J 37828 into the groove Removing The Rotor Pulley ^ Insert J 37827 over the exposed shaft. ^ Align the thumb head bolts of J 8433 to the puller fingers and tighten. Removing The Rotor Pulley (2 Of 2) ^ Turn the puller center bolt to the right with a socket wrench until the rotor pulley is free. 5. Clutch coil. ^ Loosen the coil lead wire from the clip on top of the compressor front housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6408 Removing The Coil Snap Ring ^ Remove. the snap ring. Remove the coil. Assemble Install or Connect Tools Required: J 6435 External Snap Ring Pliers J 29640 Shaft Protector J 29886 Driver Handle J 37872 Spanner Wrench J 38467 Bearing Remover and Installer 1. Clutch coil and snap ring retainer. ^ The coil flange protrusions must match the hole in the front housing to prevent coil movement and to correctly place the lead wire. Installing The Rotor Pulley 2. Rotor pulley to the front housing hub and align. ^ Place J 38467 into the bearing cavity with the outer edge on the rotor bearing outer race. ^ Place J 29886 into the ring. ^ Use a hammer to tap the end of J 29886 to guide the rotor until it bottoms out against the compressor front housing hub. Listen for a distinct change of sound during the tapping process. 3. External front housing snap ring with J 6435. 4. Front plate assembly. ^ Align the front plate keyway to the compressor shaft key. 5. J 29640 to the compressor shaft. ^ Tap the front plate to the shaft until the plate bottoms to the clutch shims. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6409 Removing The Nut 6. Shaft hex nut. ^ Hold the plate with J 37872. Tighten ^ Nut to 14 N.m (124 lbs. in.). ^ Check the air gap with a feeler gauge. It should be 0.49 to 0.79 mm (0.016 to 0.031 inch). If the gap is not consistent all around, pry up slightly at points of minimum variation. Lightly tap down at points of maximum variation. The gap is determined by the shims. If necessary, add to or remover shims from the shim stack. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor Compressor Clutch Bearing: Service and Repair With HR100/HR110-MD Compressor 4-Pole Clutch 1. Remove the Clutch Plate and Hub assembly. Removing Rotor & Bearing Assembly Retaining Ring 2. Remove Rotor and Bearing assembly retaining ring, using Snap Ring Pliers J 6083. Mark the location of the clutch coil terminals. If only the Clutch Rotor and/or Rotor Bearing are to be replaced, bend the screw head washer away from the pulley rim and remove the six (6) mounting screws before proceeding with Step 3. Discard the mounting screws. Removing Clutch Rotor Assembly 3. Install Rotor and Bearing Puller J 25031 down into the rotor until the Puller arms engage the recessed edge of the rotor hub. Hold the Puller and arms in place and tighten the Puller screw against the Puller Guide to remove the Clutch Rotor and Bearing assembly, being careful not to drop the Puller Guide. 4. If the pulley rim mounting screws were removed in Step 2, only the Clutch Rotor and Bearing assembly will be removed for replacement. The Clutch Coil and Housing assembly is pressed onto the Front Head of the compressor with a press fit and will not be removed unless the pulley rim mounting screws are left securely in place and the pulley rim pulls the Coil and Housing assembly off with the total Clutch Rotor and Pulley Rim Assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6414 Clutch Rotor Bearing Removal 5. Place the Rotor and Bearing assembly on blocks as shown in the illustration. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A. Rotor And Bearing Assembly It is not necessary to remove the staking at the rear of the rotor hub to remove the bearing. However, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore, or the bearing may be damaged. Install or Connect 1. Place the Rotor and Hub assembly face down on a clean. flat and firm surface. Installing Clutch Rotor Bearing 2. Align the new bearing squarely with the hub bore and using Pulley and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into the hub. The Installer will apply force to the outer race of the bearing if used as shown. 3. Using a center punch with a 45° angle point, stake 1.1-1.4mm (0.045-0.055" deep) the bearing in three places 120° apart as shown, but do not stake too deeply to avoid distorting the outer race of the bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6415 4. Replace rotor and bearing assembly. On-Vehicle A. Position the Rotor and Bearing assembly on the front head. Rotor And Bearing Assembly B. With Rotor & Bearing Installer J 26271-A (without driver handle) in position and Rotor and Bearing assembly aligned with the Front Head as shown in the illustration, drive the assembly part way onto the head. C. Plug clutch coil connector onto Clutch Coil. D. Position the Clutch Coil so the three (3) locating tabs will align with the holes in the head and continue to drive the Rotor and Bearing assembly onto the front head. E. Install the retainer ring. F. Reassemble the Clutch Plate and Hub with the shaft key onto the shaft with Installer J 9401-B until 0.5-7.6mm (0.020-0.030") air gap is obtained. G. Install shaft lock nut. Torque to 14 N.m (10 lb.ft.). On-Bench Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6416 Installing Rotor & Bearing Assembly Reassemble the Rotor and Bearing assembly to the front head of the compressor using Rotor & Bearing Installer J 26271-A. With Installer assembled to the Universal Handle J 29886, as shown in the illustration, force will be applied to the inner race of the bearing and the face of the rotor when installing the assembly onto the front head of the compressor. 5. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083. 6. Apply sealer include GM 12345382 (Loctite 242 or equivalent) to threads of pulley rim mounting screws. Install screws but do not torque the screws. 7. Rotate the pulley rim and rotor 10 insure that pulley rim is rotating "in-line". If pulley rim is distorted (does not rotate in-line), adjust or replace pulley rim. 8. Tighten pulley rim mounting screws to 11 N.m (100 in. lbs.) torque and lock screw heads in place by bending screw head washer similar to original crimp. 9. Reinstall Clutch Plate and Hub assembly. 6-Pole Clutch 1. Remove the clutch plate and hub assembly as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6417 Removing Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring, using Snap Ring Pliers J 6083. Removing Clutch Rotor Assembly - Poly-Groove Drive Pulley Rotor & Bearing Puller Installation 3. Install Pulley Rotor and Puller Guide J 25031 to the front head, and install J 33020 Pulley Rotor and Bearing Puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6418 Pulley Rotor & Bearing Puller Removal 4. Hold the J 33020 Puller in place and tighten the puller screw against the Puller Guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal, the rotor hub must be properly supported. Bearing Assembly Remove the forcing screw from J 33020 Puller and with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in the illustration. 6. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A and J 29886 Universal Handle. Pulley Rotor & Bearing Puller Removal It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6419 Bearing Assembly 1. Place the Pulley Rotor on the J 21352-A Support Block to fully support the rotor hub during bearing installation. Do not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using Puller and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into hub. The Installer will apply force to the outer race of the bearing if used as shown. Bearing Staking 3. Place Bearing Staking Guide J 33019-1 and Bearing Staking Pin J 33019-2 in the hub bore as shown in the illustration. Shift the rotor and bearing assembly on the J 21352-A Support Block to give full support of the hub under the staking pin location. A heavy duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide alter each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching, the bearing. Stake three (3) places 120° apart as shown. NOTICE: The stake metal should not contact the outer race of the bearing to prevent the possibility of distorting the outer race. Bearing Staked In Place 5. With the compressor mounted to the J 25008-A Holding Fixture, position the Rotor and Bearing Assembly on the front head. Using Rotor and Bearing Installer J 9481-A and Universal Handle J 29886 drive the rotor and bearing assembly onto the front head. With the Installer assembled to the Handle as shown in the illustration. force will be applied to the inner race of the bearing when installing the assembly onto the front head of the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6420 compressor. Pulley Rotor And Bearing Assembly 6. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083. 7. Reinstall clutch plate and hub assembly as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6421 Compressor Clutch Bearing: Service and Repair With V5 Compressor Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Removing Pulley Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring. using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6422 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide J 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. 4. Hold the J 33020 puller in place and tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and, with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in the illustration. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398-A and J 29886 universal handle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6423 It is not necessary to remove the staking in front of the bearing to remove the bearing, however , it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: Do Not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle 1 29886, drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing if used as shown. Staking Bearing In Rotor Hub Bore 3. Place bearing staking guide J 33019-1 and bearing staking pin 133019 in the hub bore as shown in Figure 13. Shift the rotor and bearing assembly on the J 21352-A support block to give full support of the hub under the staking pin location. A heavy-duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to but not touching the bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6424 Bearing Staked In Place The stake metal should not contact the outer face of the bearing to prevent the possibility of distorting the outer race. Stake three (3) places 120° apart as shown in the illustration. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 34992 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley rotor and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 34992-2 through bolts and washers through the puller bar slots and thread them into the J 34992 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in-line contact with the inner face of the bearing, loosen the J 8433-3 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6425 Compressor Clutch Bearing: Service and Repair With HD6/HR6-HE Compressor Remove or Disconnect 1. Remove the clutch plate and hub assembly. Installing-Removing Pulley Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring, using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6426 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide J 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots in the rotor. 4. Hold the J 33020 puller in place and tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398A and J 29886 universal handle. NOTICE: It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will he necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6427 Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: DO NOT support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle J 29886 drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing. Staking Bearing In Rotor Hub Bore 3. Place bearing staking guide J 33019-1 and bearing staking pin J 33019-2 in the hub bore. Shift the rotor and bearing assembly on the J 21352-A support block to give full support of the hub under the staking pin location. A heavy-duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury strike the staking pin with a hammer until a metal stake similar to the original is formed down to but not touching the bearing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6428 Bearing Staked In Place Noisy bearing operation and reduced bearing life may result if outer bearing race is deformed while staking, the stake metal should not contact the outer race of the bearing. Stake three places 120° apart. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 33026 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley, rotor, and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 33026-2 through bolts and washers through the puller bar slots and thread them into the J 33026 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in line contact with the inner race of the bearing, loosen the J 8433-1 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6429 Compressor Clutch Bearing: Service and Repair With SD-7H15 Compressor Disassemble Remove or Disconnect Tools Required: J 6435 External Snap Ring Pliers J 8433 Puller Set J 37825 Puller Plate Assembly J 37827 Puller Pilot J 37828 Puller Fingers J 37872 Spanner Wrench Removing The Nut ^ Insert the two pins of the J 37872 into any two threaded holes of the clutch front plate. Hold the clutch plate stationary. 1. Hex nut using a 14 mm socket. Removing The Clutch Plate 2. Clutch front plate using J 37825. ^ Align the puller center bolt to the compressor shaft. ^ Thumb tighten the three puller bolts into the threaded holes. ^ Turn the center bolt to the right with the socket wrench until the front plate is loosened. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6430 Removing The Internal Snap Ring 3. External front housing snap ring with J 6435. 4. Rotor pulley assembly. ^ Insert J 37828 into the groove Removing The Rotor Pulley ^ Insert J 37827 over the exposed shaft. ^ Align the thumb head bolts of J 8433 to the puller fingers and tighten. Removing The Rotor Pulley (2 Of 2) ^ Turn the puller center bolt to the right with a socket wrench until the rotor pulley is free. 5. Clutch coil. ^ Loosen the coil lead wire from the clip on top of the compressor front housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6431 Removing The Coil Snap Ring ^ Remove. the snap ring. Remove the coil. Assemble Install or Connect Tools Required: J 6435 External Snap Ring Pliers J 29640 Shaft Protector J 29886 Driver Handle J 37872 Spanner Wrench J 38467 Bearing Remover and Installer 1. Clutch coil and snap ring retainer. ^ The coil flange protrusions must match the hole in the front housing to prevent coil movement and to correctly place the lead wire. Installing The Rotor Pulley 2. Rotor pulley to the front housing hub and align. ^ Place J 38467 into the bearing cavity with the outer edge on the rotor bearing outer race. ^ Place J 29886 into the ring. ^ Use a hammer to tap the end of J 29886 to guide the rotor until it bottoms out against the compressor front housing hub. Listen for a distinct change of sound during the tapping process. 3. External front housing snap ring with J 6435. 4. Front plate assembly. ^ Align the front plate keyway to the compressor shaft key. 5. J 29640 to the compressor shaft. ^ Tap the front plate to the shaft until the plate bottoms to the clutch shims. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Bearing > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6432 Removing The Nut 6. Shaft hex nut. ^ Hold the plate with J 37872. Tighten ^ Nut to 14 N.m (124 lbs. in.). ^ Check the air gap with a feeler gauge. It should be 0.49 to 0.79 mm (0.016 to 0.031 inch). If the gap is not consistent all around, pry up slightly at points of minimum variation. Lightly tap down at points of maximum variation. The gap is determined by the shims. If necessary, add to or remover shims from the shim stack. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor Compressor Clutch Coil: Service and Repair With HR100/HR110-MD Compressor CLUTCH COIL AND PULLEY RIM INSTALLATION AND REMOVAL PROCEDURES FOR THE 6 POLE CLUTCH ARE THE SAME AS THE 4 POLE EXCEPT STEPS 1 THROUGH 4 OF THE CLUTCH ROTOR AND/OR BEARING - 6 POLE CLUTCH, REMOVAL OR DISCONNECT MUST BE USED. V-Groove Drive - 4 Pole Clutch Remove or Disconnect 1. Perform Steps 1 through 4 of COMPRESSOR CLUTCH ROTOR AND/OR BEARING removal procedure but do not loosen or remove the pulley rim mounting screws until the Clutch Rotor, Coil and Pulley Rim assembly have been removed from the Front Head. Be careful not to drop the Puller Guide J 25031 when removing the assembly. 2. Remove the pulley rim mounting screws and discard. Clutch Coil Assembly 3. Slide the pulley rim off the Rotor and Hub assembly The Pulley Rim and the Clutch Coil) are replaceable at this point. Install or Connect Assembling Clutch Coil, Pulley Rim, Rotor & Bearing 1. Assemble the Clutch Coil, Pulley Rim and the Clutch Rotor and Bearing assembly as shown in the illustration. Use new screws and apply sealer GM 12345382 (Loctite 242, or equivalent) to screw threads but do not lock the screws in place. Installing Rotor And Bearing Assembly (On-Vehicle) 2. Place the assembly on the neck of the Front Head and seat into place using Rotor & Bearing Installer J 26271-A. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6437 Before fully seating the assembly on the Front Head, be sure the clutch coil terminals are in the proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil align with the locator holes in the Front Head. 3. Install the rotor and bearing assembly retaining ring and reassemble the Clutch Plate and Hub assembly as described in "Compressor Clutch Plate and Hub Assembly" Replacement procedure. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.6mm (0.020-0.030"). Rotate the Pulley Rim and Rotor to be sure the Pulley Rim is rotating "in-line" and adjust or replace as required. 4. Tighten the pulley rim mounting screws to 11 N.m (100 in. lbs.) torque and lock the screw heads in place by bending screw head washer, similar to original crimp and lock bends on washers. Poly-Groove Drive Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. 2. Remove the pulley rotor and bearing assembly as described previously. Mark the location of the clutch coil terminals on the compressor. Removing Poly-Groove Clutch Coil Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6438 Removing Poly-Groove Clutch Coil (Optional Method) 3. Install Rotor and Bearing Puller Guide J 25031 to the front head and install Puller J 8433 with Poly-V-Belt Puller Leg Set J 24092 and remove the clutch coil from the front head. Clutch coil may also be removed by using rotor and bearing puller guide J 25031 with puller tool J 25287. Install or Connect 1. Place the clutch coil assembly on the neck of the front head with clutch coil terminals in line with mark described in Step 2 of the removal procedure. 2. Place the pulley rotor and bearing assembly on the neck of the front head and seat the clutch coil and pulley rotor in place using Rotor and Bearing Installer J 26271-A. Before fully seating the assembly on the front head. be sure the clutch coil terminals are in proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil housing align with the located holes in the front head. 3. Install the pulley-rotor and bearing assembly retaining ring and reassemble the clutch plate and hub assembly as described in Clutch Plate and Hub Assembly-Replace 4. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.0mm (0.020-0.030"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6439 Compressor Clutch Coil: Service and Repair With V5 Compressor Remove or Disconnect 1. Perform Steps 1 through 4 of "Clutch Rotor and/or Bearings" removal procedure. Mark clutch coil terminal location on compressor front head. Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs as shown in the illustration. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. Place the clutch coil assembly on the front head with the terminals positioned at the "marked location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. 3. Center the J 8433-1 puller crossbar in the countersunk center hole of the J 33024 clutch coil installer. Install the J 34992-2 through bolts and washers through the crossbar slots and thread them, into the holding fixture J 34992 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay "in-line" during installation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6440 Installing Clutch Coil Assembly 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three (3) places 120° apart. to ensure clutch coil remaining in position. Staking Clutch Coil To Front Head ^ Stake size should be only one half the area of the punch tip and only approximately 0.28-0.35mm (0.01-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly according as described previously. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6441 Compressor Clutch Coil: Service and Repair With HD6/HR6-HE Compressor Remove or Disconnect 1. Perform Steps 1 through 4 of Clutch Rotor and/or Bearing removal procedure. Mark clutch coil terminal location on compressor front head. Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. Place the clutch coil assembly on the front head with the terminals positioned at the "marked" location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6442 Installing Clutch Coil Assembly 3. Center the J 8433-1 puller crossbar in the counter-sunk center hole of the J 33024 clutch coil installer. Install the J 33026-2 through bolts and washers through the crossbar slots and thread them into the holding fixture J 33026 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay in-line during installation. Staking Clutch Coil To Front Head 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three places 120° apart, to ensure clutch coil remains in position. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6443 Details Of Stakes In Front Head For Clutch Coil ^ Stake size should be only one-half the area of the punch tip and be only approximately 0.28-0.35mm (0.010-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6444 Compressor Clutch Coil: Service and Repair With SD-7H15 Compressor Disassemble Remove or Disconnect Tools Required: J 6435 External Snap Ring Pliers J 8433 Puller Set J 37825 Puller Plate Assembly J 37827 Puller Pilot J 37828 Puller Fingers J 37872 Spanner Wrench Removing The Nut ^ Insert the two pins of the J 37872 into any two threaded holes of the clutch front plate. Hold the clutch plate stationary. 1. Hex nut using a 14 mm socket. Removing The Clutch Plate 2. Clutch front plate using J 37825. ^ Align the puller center bolt to the compressor shaft. ^ Thumb tighten the three puller bolts into the threaded holes. ^ Turn the center bolt to the right with the socket wrench until the front plate is loosened. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6445 Removing The Internal Snap Ring 3. External front housing snap ring with J 6435. 4. Rotor pulley assembly. ^ Insert J 37828 into the groove Removing The Rotor Pulley ^ Insert J 37827 over the exposed shaft. ^ Align the thumb head bolts of J 8433 to the puller fingers and tighten. Removing The Rotor Pulley (2 Of 2) ^ Turn the puller center bolt to the right with a socket wrench until the rotor pulley is free. 5. Clutch coil. ^ Loosen the coil lead wire from the clip on top of the compressor front housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6446 Removing The Coil Snap Ring ^ Remove. the snap ring. Remove the coil. Assemble Install or Connect Tools Required: J 6435 External Snap Ring Pliers J 29640 Shaft Protector J 29886 Driver Handle J 37872 Spanner Wrench J 38467 Bearing Remover and Installer 1. Clutch coil and snap ring retainer. ^ The coil flange protrusions must match the hole in the front housing to prevent coil movement and to correctly place the lead wire. Installing The Rotor Pulley 2. Rotor pulley to the front housing hub and align. ^ Place J 38467 into the bearing cavity with the outer edge on the rotor bearing outer race. ^ Place J 29886 into the ring. ^ Use a hammer to tap the end of J 29886 to guide the rotor until it bottoms out against the compressor front housing hub. Listen for a distinct change of sound during the tapping process. 3. External front housing snap ring with J 6435. 4. Front plate assembly. ^ Align the front plate keyway to the compressor shaft key. 5. J 29640 to the compressor shaft. ^ Tap the front plate to the shaft until the plate bottoms to the clutch shims. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Coil > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6447 Removing The Nut 6. Shaft hex nut. ^ Hold the plate with J 37872. Tighten ^ Nut to 14 N.m (124 lbs. in.). ^ Check the air gap with a feeler gauge. It should be 0.49 to 0.79 mm (0.016 to 0.031 inch). If the gap is not consistent all around, pry up slightly at points of minimum variation. Lightly tap down at points of maximum variation. The gap is determined by the shims. If necessary, add to or remover shims from the shim stack. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Specifications > With HD6/HR6-HE Compressor Compressor Clutch Hub: Specifications With HD6/HR6-HE Compressor Clutch Plate & Rotor .............................................................................................................................................................. 0.50-0.76mm (0.020-0.030") Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Specifications > With HD6/HR6-HE Compressor > Page 6452 Compressor Clutch Hub: Specifications With HR100/HR110-MD Compressor Clutch Air Gap ..................................................................................................................................... ...................................... 0.5-7.6mm (0.020-0.030") Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Specifications > With HD6/HR6-HE Compressor > Page 6453 Compressor Clutch Hub: Specifications With SD-7H15 Compressor Clutch Air Gap ........................................................................................................................................................ 0.49 to 0.79 mm (0.016 to 0.031 inch) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Specifications > With HD6/HR6-HE Compressor > Page 6454 Compressor Clutch Hub: Specifications With V5 Compressor Clutch Air Gap ..................................................................................................................................... .................................. 0.50-0.076mm (0.20-0.030") Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor Compressor Clutch Hub: Service and Repair With HR100/HR110-MD Compressor Remove or Disconnect 1. If compressor is on the vehicle, loosen compressor mounting brackets, disconnect the compressor drive belt and reposition the compressor for access, if necessary. Compressor In Holding Fixture If compressor has been removed from the vehicle, attach the compressor to Holding Fixture J 25008-A and clamp the Holding Fixture in a vise. ^ Compressor mounting holes are metric. Use proper metric bolts with holding fixture J 25008-A. Clutch Plate & Hub Assembly Removal 2. Thread the Clutch Plate and Hub Assembly Remover J 33013-B, into the hub. Hold the body of the Remover with a wrench and turn the center screw into the Remover body to remove the Clutch Plate and Hub assembly. 3. Remove the shaft key. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6457 Installing Shaft Key 1. Install the shaft key into the hub key groove. Allow the key to project approximately 4.8mm (3/16") out of the keyway. The shaft key is curved slightly to provide an interference lit in the shaft key groove of the hub. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the Clutch Plate and Hub assembly. 3. Align the shaft key with the shaft keyway and place the Clutch Plate and Hub assembly onto the compressor shaft. NOTICE: To avoid internal damage to the compressor, do not drive or pound on the clutch hub or shaft. Installing Clutch Plate & Hub Assembly 4. Install the Clutch Plate and Hub Installer J 9401-B as illustrated. 5. Hold the hex portion of the Installer Body J 9401-B with a wrench and tighten the center screw to press the hub onto the shaft until there is a 0.5-7.6mm (0.020-0.030") air gap between the frictional surfaces of the clutch plate and clutch rotor. 6. If operation is performed with compressor on vehicle, connect drive belt, tighten mounting brackets and adjust belt tension. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6458 Compressor Clutch Hub: Service and Repair With V5 Compressor Remove or Disconnect Removing Shaft Nut 1. Clamp the holding fixture J 34992 in a vise and attach compressor to holding fixture with thumb screws J 34992-1. 2. Keep the clutch hub and drive plate assembly from turning by using the clutch hub holding tool J 33027-A. Remove the shaft nut using shaft nut socket J 33022. Clutch Plate And Hub Assembly Removal 3. Thread the Clutch Plate and Hub Assembly Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6459 4. Remove the shaft key and retain for reassembly. Install or Connect Shaft Key, Clutch Plate/Hub Installation 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2 mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interference fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assembly. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor shaft. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to compressor may result. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6460 Installing Clutch Plate & Hub Assembly 4. Remove the J 33013-B remover-installer center screw and reverse the body direction on the center screw as shown in the illustration. 5. Install the clutch plate and hub installer J 33013-B with bearing as shown in the illustration. The body of the J 33013-B installer should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer J 33013-B body to press the hub onto the shaft. Tighten the body several turns, remove the installer and check to see that the shaft key is still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.5-0.076mm (0.20-0.030"). ^ If the center screw is threaded fully onto the end of the compressor shaft, or if the body of the installer is held and the center screw is rotated, the key will assume the position as shown in the illustration and will break the clutch hub. 7. Remove installer J 33013-B. check for proper positioning of the shaft key (even or slightly above the clutch hub). Install the shaft nut. Hold the clutch plate and hub assembly with clutch hub holding tool J 33027-A and using shaft nut socket J 33022, tighten the nut against the crankshaft shoulder to 16.5 N.m (12 lbs.ft.) torque, using a 17.5 N.m (12.5 lbs.ft.) torque wrench. 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6461 Compressor Clutch Hub: Service and Repair With HD6/HR6-HE Compressor Remove or Disconnect Clutch Plate And Hub Assembly Removal 1. Clamp the holding fixture J 33020 in a vise and attach compressor to holding fixture with thumb screws J 33026-1. 2. With center screw forcing tip in place to thrust against the end of the shaft, thread the Clutch Plate and Hub Assembly installer-Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to the compressor may result. The forcing tip on J 33013-B remover-installer screw must be flat or the end of the shaft/axial plate assembly will be damaged. 3. Remove the shaft key and retain for assembly. Install or Connect Shaft Key, Clutch Plate/Hub Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6462 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interferance fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assemblies. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor Installing Clutch Plate & Hub Assembly 4. Remove the forcing tip on J 33013-B clutch plate and hub assembly installer-remover center screw and reverse the body direction on the center screw. Removing Pulley Rotor And Bearing Assembly 5. Install the clutch plate and hub installer-remover J 33013-B with bearing. The body of the J 33013-B installer-remover should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer-remover J 33013-B body to press the hub onto the shaft. Tighten the body several turns, remove the installer and check to see that the shaft key is still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.50-0.76mm (0.020-0.030"). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6463 NOTICE: If the center screw is threaded fully onto the end of the compressor shaft, or if the body of the installer is held and the center screw is rotated, the key will wedge and will break the clutch hub. 7. Remove installer J 33013-B, check for proper positioning of the shaft key (even or slightly above the clutch hub). 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6464 Compressor Clutch Hub: Service and Repair With SD-7H15 Compressor Disassemble Remove or Disconnect Tools Required: J 6435 External Snap Ring Pliers J 8433 Puller Set J 37825 Puller Plate Assembly J 37827 Puller Pilot J 37828 Puller Fingers J 37872 Spanner Wrench Removing The Nut ^ Insert the two pins of the J 37872 into any two threaded holes of the clutch front plate. Hold the clutch plate stationary. 1. Hex nut using a 14 mm socket. Removing The Clutch Plate 2. Clutch front plate using J 37825. ^ Align the puller center bolt to the compressor shaft. ^ Thumb tighten the three puller bolts into the threaded holes. ^ Turn the center bolt to the right with the socket wrench until the front plate is loosened. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6465 Removing The Internal Snap Ring 3. External front housing snap ring with J 6435. 4. Rotor pulley assembly. ^ Insert J 37828 into the groove Removing The Rotor Pulley ^ Insert J 37827 over the exposed shaft. ^ Align the thumb head bolts of J 8433 to the puller fingers and tighten. Removing The Rotor Pulley (2 Of 2) ^ Turn the puller center bolt to the right with a socket wrench until the rotor pulley is free. 5. Clutch coil. ^ Loosen the coil lead wire from the clip on top of the compressor front housing. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6466 Removing The Coil Snap Ring ^ Remove. the snap ring. Remove the coil. Assemble Install or Connect Tools Required: J 6435 External Snap Ring Pliers J 29640 Shaft Protector J 29886 Driver Handle J 37872 Spanner Wrench J 38467 Bearing Remover and Installer 1. Clutch coil and snap ring retainer. ^ The coil flange protrusions must match the hole in the front housing to prevent coil movement and to correctly place the lead wire. Installing The Rotor Pulley 2. Rotor pulley to the front housing hub and align. ^ Place J 38467 into the bearing cavity with the outer edge on the rotor bearing outer race. ^ Place J 29886 into the ring. ^ Use a hammer to tap the end of J 29886 to guide the rotor until it bottoms out against the compressor front housing hub. Listen for a distinct change of sound during the tapping process. 3. External front housing snap ring with J 6435. 4. Front plate assembly. ^ Align the front plate keyway to the compressor shaft key. 5. J 29640 to the compressor shaft. ^ Tap the front plate to the shaft until the plate bottoms to the clutch shims. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Clutch Hub > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6467 Removing The Nut 6. Shaft hex nut. ^ Hold the plate with J 37872. Tighten ^ Nut to 14 N.m (124 lbs. in.). ^ Check the air gap with a feeler gauge. It should be 0.49 to 0.79 mm (0.016 to 0.031 inch). If the gap is not consistent all around, pry up slightly at points of minimum variation. Lightly tap down at points of maximum variation. The gap is determined by the shims. If necessary, add to or remover shims from the shim stack. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > Customer Interest: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch Compressor Shaft Seal: Customer Interest A/C - Insufficient Performance/Noisy Clutch File In Section: 1 - HVAC Bulletin No.: 63-12-16 Date: December, 1996 Subject: Insufficient A/C Performance and/or Noisy Compressor Clutch Assembly Models: 1994-95 Chevrolet Camaro 1994-95 Pontiac Firebird 1994-95 Chevrolet and GMC G/M/L Models Condition Some owners may comment on insufficient air conditioning performance and/or noisy compressor clutch assembly. Cause Premature wear of the compressor shaft seals. This wear will result in PAG oil leakage on the clutch drive and pulley, thus causing insufficient engagement of the compressor. Correction Install new shaft seal kit, P/N 2724954 and clutch driver, P/N 6580590. Procedure 1. Recover refrigerant. Refer to "Refrigerant Recovery" in Section 1B of the Service Manual. 2. Remove clutch driver plate and hub assembly as identified in Section 1D2 of the Service Manual. 3. Before removing the compressor shaft seals, the clutch pulley rotor face must be lightly sanded with 100 grit emery cloth to remove any burnt oil build up. Once the rotor face has been reconditioned, clean area thoroughly. If the clutch pulley rotor face is badly discolored and/or damaged, replace compressor assembly. 4. Remove compressor shaft seals as identified in Section 1D2 of the Service Manual. 5. Install the new shaft seal kit, P/N 2724954, and clutch driver, P/N 6580590, using the installation procedures in Section 1D2 of the Service Manual. This new seal kit will include oil wick pads and a shaft dust seal along with the typical compressor seals. Follow the detailed instructions included in the service kit to identify proper seal usage and sequence of installation. 6. Evacuate and re-charge the system as identified in Section 1B of the Service Manual. 7. Check system for leaks. Refer to "Leak Testing" in Section 1B of the Service Manual. Parts Information P/N Description Quantity 2724954 Shaft Seal Kit, 1 Compressor 6580590 Clutch Driver, 1 Compressor Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > Customer Interest: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch > Page 6476 Labor Operation Description Labor Time D4300 Seal, Seat and/or Use published O-Ring labor operation Compressor Shaft time - Replace Add Recondition Clutch 0.1 hr Surface Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Compressor Shaft Seal: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch Compressor Shaft Seal: All Technical Service Bulletins A/C - Insufficient Performance/Noisy Clutch File In Section: 1 - HVAC Bulletin No.: 63-12-16 Date: December, 1996 Subject: Insufficient A/C Performance and/or Noisy Compressor Clutch Assembly Models: 1994-95 Chevrolet Camaro 1994-95 Pontiac Firebird 1994-95 Chevrolet and GMC G/M/L Models Condition Some owners may comment on insufficient air conditioning performance and/or noisy compressor clutch assembly. Cause Premature wear of the compressor shaft seals. This wear will result in PAG oil leakage on the clutch drive and pulley, thus causing insufficient engagement of the compressor. Correction Install new shaft seal kit, P/N 2724954 and clutch driver, P/N 6580590. Procedure 1. Recover refrigerant. Refer to "Refrigerant Recovery" in Section 1B of the Service Manual. 2. Remove clutch driver plate and hub assembly as identified in Section 1D2 of the Service Manual. 3. Before removing the compressor shaft seals, the clutch pulley rotor face must be lightly sanded with 100 grit emery cloth to remove any burnt oil build up. Once the rotor face has been reconditioned, clean area thoroughly. If the clutch pulley rotor face is badly discolored and/or damaged, replace compressor assembly. 4. Remove compressor shaft seals as identified in Section 1D2 of the Service Manual. 5. Install the new shaft seal kit, P/N 2724954, and clutch driver, P/N 6580590, using the installation procedures in Section 1D2 of the Service Manual. This new seal kit will include oil wick pads and a shaft dust seal along with the typical compressor seals. Follow the detailed instructions included in the service kit to identify proper seal usage and sequence of installation. 6. Evacuate and re-charge the system as identified in Section 1B of the Service Manual. 7. Check system for leaks. Refer to "Leak Testing" in Section 1B of the Service Manual. Parts Information P/N Description Quantity 2724954 Shaft Seal Kit, 1 Compressor 6580590 Clutch Driver, 1 Compressor Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Compressor Shaft Seal: > 63-12-16 > Dec > 96 > A/C - Insufficient Performance/Noisy Clutch > Page 6482 Labor Operation Description Labor Time D4300 Seal, Seat and/or Use published O-Ring labor operation Compressor Shaft time - Replace Add Recondition Clutch 0.1 hr Surface Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Compressor Shaft Seal: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart Compressor Shaft Seal: All Technical Service Bulletins A/C Compressor Seal Washer - Reference Chart File In Section: 1 - HVAC Bulletin No.: 63-12-15 Date: November, 1996 INFORMATION Subject: Reference Chart for A/C Compressor Seal Washers Models: 1997 and Prior Passenger Cars (Except Corvette and GEO) 1997 and Prior Light Duty Trucks (Except Tracker) GMSPO A/C compressors include a seal washer kit. These kits contain various color edge painted washer seals and inserts in which only two (2) washers and possibly one (1) insert are used. It has come to our attention that some packaging discrepancies were found and some of the seals cannot be properly identified for installation. These seals are very close in size and some of the seals were inadvertently edge painted the wrong color or not painted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Compressor Shaft Seal: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 6487 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Compressor Shaft Seal: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 6488 The chart shown will help to properly identify the seals. Use the chart by placing the seal over the pictured seal to identity inside and outside diameters and thickness. Because these seals are very similar in size, specifications are also listed in the chart. Important: If seals are damaged upon installation, obtain new seal kit. Seals will be available separately at a later date. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Other Service Bulletins for Compressor Shaft Seal: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart Compressor Shaft Seal: All Technical Service Bulletins A/C Compressor Seal Washer - Reference Chart File In Section: 1 - HVAC Bulletin No.: 63-12-15 Date: November, 1996 INFORMATION Subject: Reference Chart for A/C Compressor Seal Washers Models: 1997 and Prior Passenger Cars (Except Corvette and GEO) 1997 and Prior Light Duty Trucks (Except Tracker) GMSPO A/C compressors include a seal washer kit. These kits contain various color edge painted washer seals and inserts in which only two (2) washers and possibly one (1) insert are used. It has come to our attention that some packaging discrepancies were found and some of the seals cannot be properly identified for installation. These seals are very close in size and some of the seals were inadvertently edge painted the wrong color or not painted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Other Service Bulletins for Compressor Shaft Seal: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 6494 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Technical Service Bulletins > All Other Service Bulletins for Compressor Shaft Seal: > 631215 > Nov > 96 > A/C Compressor Seal Washer - Reference Chart > Page 6495 The chart shown will help to properly identify the seals. Use the chart by placing the seal over the pictured seal to identity inside and outside diameters and thickness. Because these seals are very similar in size, specifications are also listed in the chart. Important: If seals are damaged upon installation, obtain new seal kit. Seals will be available separately at a later date. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor Compressor Shaft Seal: Service and Repair With HR100/HR110-MD Compressor Shaft Seal Design The shaft seal is a lip seal, one piece design. Seal Leak Detection A shaft seal should not be changed because of an oil-line on the hood insulator. Only change a shaft seal when a leak is detected by evidence of oil sprayed in large amounts and then only after actual refrigerant leakage is found by using an approved leak Detector such as J 39400 or equivalent. On-Vehicle Remove or Disconnect 1. Recover Refrigerant. 2. Loosen and reposition compressor in mounting brackets, if necessary. 3. Remove Clutch Plate and Hub assembly from compressor as described in Minor Repairs. 4. Remove the shaft seal seat retainer ring, using Snap Ring Pliers J 5403. 5. Thoroughly clean inside of compressor neck area and O-ring groove surrounding the shaft, the exposed portion of the seal seat and the shaft itself. Any dirt or foreign material getting into compressor may cause damage. 6. Remove Lip Seal: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6498 Removing And Installing Seal And O-Ring (One Piece Seal) Fully engage the knurled tangs of Seal Remover-Installer J 23128-A into the recessed portion of the Seal by turning the handle clockwise. Remove the Seal from the compressor with a rotary-pulling motion. Discard the Seal. The handle must be hand-tightened securely. Do not use a wrench or plier. 7. Remove and discard the seal seat O-ring from the compressor. neck using O-ring Remover J 9553-01. 8. Recheck the shaft and inside of the compressor neck and O-ring groove for dirt or foreign material and be sure these areas are perfectly clean before installing new parts. Inspection Seals should not be reused. Always use a new specification service seal kit on rebuild. Care should be taken to prevent damage to the lip of the one piece Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6499 seal. Make sure that the Seal Seat and Seal Lip are free of lint and dirt that could damage the seal surface or prevent sealing. On-Vehicle Install or Connect 1. Dip the new seal O-ring in clean 525 viscosity refrigerant oil and assemble onto O-ring Installer J 33011. 2. Insert the O-ring Installer J 33011 completely down into the compressor neck until the Installer "bottoms". Lower the moveable slide of the O-ring Installer to release the O-ring into the seal seat O-ring lower groove. (The compressor neck top groove is for the shaft seal retainer ring.) Rotate the Installer to seat the O-ring and remove the Installer. 3. Prepare Lip Seal: ^ Assemble Lip Seal to Seal Installer, J 23128-A. The printed/stamped steel case side of Lip Seal must be engaged with knurled tangs of installer so that flared-out side of Lip Seal is facing and installed towards the compressor. 4. Install Lip Seal: ^ Place Seal Protector J 34614 over end of compressor shaft and slide new seal onto the shaft until it stops. Disengage installer from seal and remove seal protector from compressor shaft. NOTICE: Handling and care of seal protector is important. If seal protector is nicked or the bottom flared, the new seal may be damaged during installation. Removing And Installing Shaft Seal Seat Retaining Ring 5. Install the new seal seat retainer ring with its flat side against the Seal Seat, using Snap-Ring Pliers J 5403. Use the sleeve from O-ring Installer J 33011 to press in on the seal seat retainer ring so that it snaps into its groove. 6. Evacuate and charge system with 1 lb. refrigerant. Temporarily install the shaft nut and, with the compressor in horizontal position, rotate the compressor shaft in normal direction of rotation several times. Leak test the seal. Recover refrigerant and repair as necessary. Remove, discard and later replace the shaft nut. 7. Remove any excess oil, resulting from installing the new seal parts, from the shaft and inside the compressor neck. 8. Install the Clutch Plate and Hub assembly as described in minor repair procedures. 9. Reinstall compressor belt and tighten bracketry. 10. Evacuate and Charge the Refrigerant System. Off-Vehicle Install or Connect 1. Follow applicable on-vehicle procedures. 2. To leak test. install compressor leak test fixture J 9625-A on rear head of compressor and connect gage charging lines and J 38100-B Refrigerant Recovery System. Pressurize suction and high-side of compressor with Refrigerant-12 vapor to drum pressure. Temporarily install (M9 x 1.25 thread on shaft) nut and, with the compressor in horizontal position, rotate the compressor shaft in normal direction of rotation several turns by hand. Leak test the seal area and correct any leak found. Recover the refrigerant. Remove shaft nut. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6500 Compressor Shaft Seal: Service and Repair With HD6/HR6-HE Compressor Seal Leak Detection A shaft seal should not be changed because of small amounts of oil found on an adjacent surface but only after actual refrigerant leakage is found using an approved leak detector, J 39400 or equivalent. Remove or Disconnect 1. Recover the refrigerant using J 39500-GM. 2. Loosen and reposition compressor in mounting brackets if necessary. 3. Remove clutch plate and hub assembly from compressor as described in minor repairs. Removing Or Installing Shaft Seal Retaining Ring 4. Remove the shaft seal retainer ring using snap ring pliers J 5403. 5. Thoroughly clean inside of compressor neck area surrounding the shaft, the exposed portion of the seal, the retainer ring groove and the shaft itself. Any dirt or foreign material getting in to compressor may cause damage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6501 Removing Or Installing Shaft Seal 6. Fully engage the knurled tangs of Seal Remover/Installer J 23128-A into the recessed portion of the seal by turning the handle clockwise. Remove the seal from the compressor with a rotary-pulling motion. Discard the seal. The handle must be hand-tightened securely. Do not use a wrench or pliers. 7. Remove and discard the seal seat O-ring from the compressor neck using O-ring remover J 95534-1. 8. Recheck the shaft and inside of the compressor neck for dirt or foreign material and be sure these areas are perfectly clean before installing new parts. Clean ^ Thoroughly clean O-ring seal groove in front head. Compressor Shaft Seal NOTICE: Seals should not be re-used. Always use a new specification service seal on rebuild. Be sure that the seal to be installed is not scratched or damaged in anyway. Make sure that the seal seat and seal are free of lint and dirt that could damage the seal surface or prevent sealing. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6502 Removing And Installing Shaft Seal And O-Ring 1. Dip the new seal seat O-ring in clean 525 viscosity refrigerant oil and assemble onto O-ring installer J 33011. 2. Insert the O-ring installer J 33011 into the compressor neck until the installer "bottoms". Lower the moveable slide of the O-ring installer to release the O-ring into the seal O-ring lower groove. (The compressor neck top groove is for the shaft seal retainer ring.) Rotate the installer to seat the O-ring and remove the installer. 3. Dip the new seal in clean 525 viscosity refrigerant oil and assemble seal to Seal Installer J 23128-A by turning handle clockwise. The stamped steel case side of the lip seal must be engaged with knurled tangs of installer so that flared-out side of lip seal is facing and installed towards the compressor. Install seal protector J 34614 in the seal lip and place over the compressor shaft and push the seal in place with a rotary motion or Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6503 place the seal protector J 34014 over end of compressor shaft. Slide the new seal onto the shaft with a rotary motion until it stops. Take care not to dislodge the O-ring. Be sure the seal makes good contact with the O-ring. Disengage the installer from the seal and remove the installer J 23128-A and the seal protector J 34614. NOTICE: Handling and care of seal protector is important. If seal protector is nicked or the bottom flared, the new seal may be damaged during installation. 4. Install the new seal retainer ring with its flat side against the Seal, using Snap-Ring Pliers J 5403. Use the sleeve from O-ring installer J 33011 to press in on the seal retainer ring so that it snaps into its groove. 5. To leak test, install compressor leak test fixture J 39893 on rear head of compressor and connect gage charging lines and J 39500-GM Refrigerant Recovery System. Pressurize suction and high-side of compressor with R-134a Refrigerant. Temporarily install (M9 x 1.25 thread on shaft) nut and, with the compressor in horizontal position, rotate the compressor shaft in normal direction of rotation several turns by hand. Leak test the seal area and correct if leak found. Recover the refrigerant. Remove shaft nut. 6. Remove any excess oil resulting from installing the new seal parts from the shaft and inside the compressor neck. 7. Install the clutch plate and hub assembly as described in minor repair procedures. 8. Reinstall compressor belt and tighten bracket. 9. Evacuate and charge the refrigerant system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6504 Compressor Shaft Seal: Service and Repair With V5 Compressor Seal Leak Detection A shaft seal should not be changed because of small amounts of oil found on an adjacent surface. The seal is designed to leak some oil for lubrication purposes. A shaft seal should be changed only when a large amount of sprayed oil is found, and only after actual refrigerant leakage is found by using an approved leak detection procedure. Remove or Disconnect 1. Recover refrigerant. 2. Loosen and reposition compressor in mounting brackets. 3. Remove clutch plate and hub assembly from compressor as described in minor repairs. Removing Or Installing Shaft Seal Retaining Ring 4. Remove the shaft seal retainer ring, using snap ring pliers J 5403. 5. Thoroughly clean inside of compressor neck area surrounding the shaft, the exposed portion of the seal, the shaft itself and O-ring groove. Any dirt or foreign material getting into compressor may cause damage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6505 Removing Shaft Seal 6. Fully engage the knurled tangs of seal remover-installer J 23128-A into the recessed portion of the seal by turning the handle clockwise. Remove the seal from the compressor with a rotary-pulling motion. Discard the seal. The handle should be hand-tightened securely. Do not use a wrench or pliers. Removing Or Installing Shaft Seal O-Ring 7. Remove and discard the seal O-ring from the compressor neck using O-ring remover J 9553-01. 8. Thoroughly clean seal O-ring groove in front head. 9. Recheck the shaft and inside of the compressor neck for dirt or foreign material and be sure these areas are perfectly clean before installing new parts. Inspect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Compressor HVAC > Compressor Shaft Seal > Component Information > Service and Repair > With HR100/HR110-MD Compressor > Page 6506 Seals should not be re-used. Always use a new specification service seal kit. Be sure that the seal to be installed is not scratched or damaged in any way. Make sure that the seal is free of lint and dirt that could damage the seal surface or prevent sealing. Install or Connect 1. Dip the new seal O-ring in clean 525 viscosity refrigerant oil and assemble onto O-ring installer J 33011. 2. Insert the O-ring installer J 33011 into the compressor neck until the installer "bottoms." Lower the moveable slide of the O-ring installer to release the O-ring into the seal O-ring lower groove. (The compressor neck top groove is for the shaft seal retainer ring.) Rotate the installer to seat the O-ring and remove the installer. Lip Seal Installed On Seal Protector 3. Attach the seal to the seal remover and installer J 23128-A and dip the seal in clean 525 viscosity refrigerant oil to coat the seal. Install seal protector J 34614 in the seal, place over shaft and push seal in place with a rotary motion. 4. Install the new seal retainer ring with its flat side against the seal, using snap-ring pliers J 5403. Use the sleeve from O-ring installer J 33011 to press in on the seal retainer ring so that it snaps into its groove. 5. To leak test, install compressor leak test fixture J 9625-A on rear head of compressor and connect gage charging lines using J 38100-C Refrigerant Recovery System. Pressurize suction and high-side of compressor with Refrigerant 12 vapor to drum pressure. Temporarily install the shaft nut and, with the compressor in horizontal position. rotate the compressor shaft in normal direction of rotation several turns by hand. Leak test the seal area and correct any leak found. Recover refrigerant. Remove shaft nut. 6. Remove any excess oil resulting from installing the new seal parts from the shaft and inside the compressor neck. 7. Install the clutch plate and hub assembly as described in minor repair procedures. 8. Reinstall the compressor, belt and tighten bracket. 9. Evacuate and charge the refrigerant system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Condenser HVAC > Component Information > Service and Repair Condenser HVAC: Service and Repair Condenser Evaporator Tube REMOVE OR DISCONNECT 1. Discharge and recover refrigerant from the system. 2. Grille and front-end panel. 3. Radiator bar support. 4. Compressor and condenser hose from the condenser. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Condenser HVAC > Component Information > Service and Repair > Page 6510 5. Evaporator tube from the condenser. 6. Insulator bracket bolts. 7. Insulator brackets. 8. Upper insulators. 9. Condenser. INSTALL OR CONNECT 1. Condenser. Refer to Refrigerant Oil Distribution, if replacing the condenser. See: Specifications/Capacity Specifications 2. Upper insulators. 3. Insulator brackets. 4. Insulator bracket bolts. ^ Tighten bolts to 27 N.m (20 lbs. ft.). 5. Evaporator tube to the condenser. 6. Compressor and condenser hose to the condenser. 7. Radiator bar support. 8. Grille and front-end panel. 9. Refrigerant to the system. ^ Check the system for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Locations > Auxiliary Heater Control Switch Heater-A/C Controls And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Locations > Auxiliary Heater Control Switch > Page 6515 Air Conditioning, Heater Control I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Locations > Auxiliary Heater Control Switch > Page 6516 Air Conditioning, Heater Control I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) Control Assembly: Diagrams Actuators and Control Schematic (With A/C) Control Assembly Operating Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6519 Schematic Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6520 Control Assembly: Diagrams Vacuum Harness Routing Vacuum Hose Routing, Engine Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6521 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Diagrams > Page 6522 Control Assembly Operational Test Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Service and Repair > With Air Conditioning Control Assembly: Service and Repair With Air Conditioning Front Control Assembly Replacement Control Assembly Wiring Connectors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Service and Repair > With Air Conditioning > Page 6525 Temp, Defrost And Vent Cables REMOVE OR DISCONNECT 1. Screws. 2. Control assembly. ^ Pull control assembly out of the instrument panel far enough to reach the control cable assembly ends and the blower switch electrical connector. 3. Electrical connector(s), as necessary. 4. Control cables. 5. Blower switch, if necessary. ^ Remove the blower switch knob and spring clip, and remove the blower switch. INSPECT ^ Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. ^ Temperature and mode levers for freedom of movement. Lubricate, repair, or replace as necessary. ^ Control cable assemblies for kinks, binding and other damage. Repair or replace as necessary. INSTALL OR CONNECT Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Service and Repair > With Air Conditioning > Page 6526 1. Heater blower switch, if removed. ^ Hold the blower switch in position and install the spring clip. ^ Install the blower switch knob. 2. Control cables. 3. Electrical connector(s), as necessary. 4. Control assembly. 5. Screws. ^ Tighten screws to 1.4 N.m (12 in. lbs.). ^ Check circuit operation. Rear Air Conditioning Auxiliary Control Switch REMOVE OR DISCONNECT 1. Control switch. 2. Electrical connection. INSTALL OR CONNECT 1. Electrical connection. 2. Control switch. ^ Check circuit operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Service and Repair > With Air Conditioning > Page 6527 Control Assembly: Service and Repair Without Air Conditioning Front Control Assembly Replacement Control Assembly Wiring Connectors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Service and Repair > With Air Conditioning > Page 6528 Temp, Defrost And Vent Cables REMOVE OR DISCONNECT 1. Screws. 2. Control assembly. ^ Pull control assembly out of the instrument panel far enough to reach the control cable assembly ends and the blower switch electrical connector. 3. Electrical connector(s), as necessary. 4. Control cables. 5. Blower switch, if necessary. ^ Remove the blower switch knob and spring clip, and remove the blower switch. INSPECT ^ Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. ^ Temperature and mode levers for freedom of movement. Lubricate, repair, or replace as necessary. ^ Control cable assemblies for kinks, binding and other damage. Repair or replace as necessary. INSTALL OR CONNECT Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Control Assembly, HVAC > Component Information > Service and Repair > With Air Conditioning > Page 6529 1. Heater blower switch, if removed. ^ Hold the blower switch in position and install the spring clip. ^ Install the blower switch knob. 2. Control cables. 3. Electrical connector(s), as necessary. 4. Control assembly. 5. Screws. ^ Tighten screws to 1.4 N.m (12 in. lbs.). ^ Check circuit operation. Rear Auxiliary Control Switch REMOVE OR DISCONNECT 1. Control switch. 2. Electrical connection. INSTALL OR CONNECT 1. Electrical connection. 2. Control switch. ^ Check circuit operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System Evaporator Core: Customer Interest A/C - Musty Odors Emitted From (HVAC) System TECHNICAL Bulletin No.: 99-01-39-004C Date: June 12, 2009 Subject: Air Conditioning Odor (Install Evaporator Core Dryer Kit and Apply Cooling Coil Coating) Models: 1993-2010 GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 All Equipped with Air Conditioning Supercede: This bulletin is being revised to add the 2009 and 2010 model years. Please discard Corporate Bulletin Number 99-01-39-004B (Section 01 - HVAC). Condition Some customers may comment about musty odors emitted from the Heating, Ventilation and Air Conditioning (HVAC) system at vehicle start-up in hot, humid conditions. Cause This condition may be caused by condensate build-up on the evaporator core, which does not evaporate by itself in high humidity conditions. The odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. There are several other possible sources of a musty odor in a vehicle. A common source is a water leak into the interior of the vehicle or foreign material in the HVAC air distribution system. Follow the procedures in SI for identifying and correcting water leaks and air inlet inspection. The procedure contained in this bulletin is only applicable if the odor source has been determined to be microbial growth on the evaporator core inside the HVAC module. Correction Many vehicles currently incorporate an afterblow function within the HVAC control module software. The afterblow feature, when enabled, employs the HVAC blower fan to dry the evaporator after vehicle shut down and this function will inhibit microbial growth. Technicians are to confirm that the customer concern is evaporator core odor and that the vehicle has the imbedded afterblow feature, as defined in the SI document for that specific vehicle model, model year and specific HVAC option. Refer to SI for enabling the afterblow function. Vehicles being delivered in areas prone to high humidity conditions may benefit from having the afterblow enabled calibration installed prior to any customer comment. Important If the vehicle is not factory equipped with the imbedded afterblow enable feature, it may be added with the Electronic Evaporator Dryer Module Kit (P/N 12497910 or AC Delco 15-5876). Important When installing the Electronic Evaporator Dryer Module, you MUST use the included electrical splice connectors to ensure a proper splice. Complete detailed installation instructions and self testing procedures are supplied with the kit. If necessary, the Electronic Evaporator Dryer Module may be installed underhood if it is protected from extreme heat and water splash areas. To immediately remove the evaporator core odor on all suspect vehicles, it is necessary to eliminate the microbial growth and prevent its re-occurrence. To accomplish this, perform the following procedure: Vehicle and Applicator Tool Preparation 1. The evaporator core must be dry. This may be accomplished by disabling the compressor and running the blower fan on the recirc heat setting for an extended period of time. Note Compressor engagement will cause the evaporator core to remain wet and will prevent full adherence of the Coiling Coil Coating to the evaporator core surfaces. 2. Verify that the air conditioning drain hose is not clogged and place a drain pan beneath the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 6538 3. Place a protective cover over the carpet below the evaporator core. 4. Remove the cabin air filter, if equipped, and cover the opening prior to applying the Cooling Coil Coating, as the product may clog the filter. If the cabin air filter appears to have little or no remaining life, suggest a replacement to your customer. 5. If the HVAC module has a blower motor cooling tube, be careful NOT TO SPRAY THE COOLING COIL COATING INTO THE BLOWER MOTOR COOLING TUBE. 6. Attach the Flexible Applicator Pressure Spray Tool (J-43810-20A) to a compressed air line operating at 586 kPa (85 psi) to 793 kPa (115 psi). 7. Shake the bottle of Cooling Coil Coating well. Screw the bottle onto the cap on the applicator tool's pick-up tube. Note The pick-up tube is designed for 120 ml (4 oz) and 240 ml (8 oz) bottles and should coil slightly in the bottom of a 120 ml (4 oz) bottle. 8. Use one of the following three methods to apply the Cooling Coil Coating. Important If the Pressure Applicator Spray Tool (J-43810-20A) is not available, the Cooling Coil Coating is also available in an aerosol can (P/N 12377951 (in Canada, 10953503)). Application Through Blower Motor Control Module Opening - Remove the blower motor control module (blower motor resistor). Refer to the applicable procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor blower motor control module (blower motor resistor) opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor blower motor control module (blower motor control module). Application Through Blower Motor Opening - Remove the blower motor. Refer to the applicable blower motor removal procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor. Application Through a Hole in the HVAC Module - If neither of the two previous application methods are available, it may be necessary to drill a hole in the HVAC module. - Locate an area of the HVAC module between the blower motor and the evaporator core. Drill a 10 mm (3/8 in) hole in the HVAC module. Use caution to keep the drill clear of the evaporator core and the blower motor fan. - With the air distribution vents closed and the blower motor fan speed on HIGH, insert the applicator tool into the hole and spray the Cooling Coil Coating into the airstream toward the evaporator core. - Use a GM approved RTV sealant to plug the hole in the HVAC module. 9. After the Cooling Coil Coating application is complete, start and run the vehicle for approximately 10 minutes, with the compressor disabled, HVAC mode set to Recirculate/Max, heat set to full warm, blower motor fan speed on high, and one window open approximately 12 mm (1/2 in). This cures the Cooling Coil Coating onto the evaporator core surface. 10. While the engine is running, rinse the applicator tool with warm water to prolong the life of the tool. Be sure to spray warm water through the nozzle to rinse out any residual Cooling Coil Coating still in the capillary pick up tube, otherwise it will dry and clog the applicator tool. Also remove the small green valve from the bottle cap and rinse it thoroughly while rolling it between two fingers and then reinstall it. If this valve is clogged , the Cooling Coil Coating will not flow through the applicator tool. 11. Shut off the engine and enable the compressor again. 12. Verify proper HVAC system operation. 13. Remove the protective cover from inside the vehicle. 14. Remove the drain pan from underneath the vehicle. 15. Reinstall the cabin air filter if necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 6539 Parts Information Important The Cooling Coil Coating listed below is the only GM approved product for use under warranty as an evaporator core disinfectant and for the long term control of evaporator core microbial growth. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates Evaporator Core: Customer Interest A/C - Odor at Start up in Humid Climates File In Section: 1 - HVAC Bulletin No.: 53-12-12A Date: December, 1996 Subject: Air Conditioning Odor at Start Up in Humid Climates (Disinfect Evaporator Core, Install Delayed Blower Control Package) Models: 1993-96 Passenger Cars (Except GEO) 1993-96 Light Duty Models (Except Tracker) This bulletin is being revised to update the wiring diagrams, add the Corvette (with RPO C60) and delete medium/heavy duty trucks. Please discard Corporate Bulletin Number 53-12-12 (Section 1 HVAC). Condition Some owners may comment on odors emitted from the air conditioning system, primarily at start up in hot, humid climates. Cause This odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. Correction To remove odors of this type, it is necessary to eliminate the microbial growth and prevent its recurrence. To accomplish this, these two procedures must be completed. ^ Deodorize the evaporator core using Deodorizing Aerosol Kit, P/N 12377951 (AC Delco 15-102). ^ Install the new A/C Delayed Blower Control Package, P/N 12370470, (AC Delco 15-8632). The blower control package will enable the blower to run at high speed for five (5) minutes. It will do so approximately fifty (50) minutes after the ignition has been turned off if the compressor had been engaged for four (4) or more minutes prior to shutting off engine. By doing so, the evaporator case and core are dried out, reducing the chances of a recurring A/C odor. Procedure 1. Visually inspect the air conditioning evaporator drain hose for obstructions or working condition. 2. Apply deodorizing aerosol as described in the instructions supplied with the kit. Once the deodorizer has been applied, some of the mixture may overflow from the drain hose. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6544 3. The chart identifies specific instructions for each vehicle. This chart will identify the proper deodorizing procedure, template and wiring diagram. Deodorizing the evaporator case can easily be done by removing the blower motor resistor and tape off opening. The nozzle can now be inserted through a pierced hole in the tape to deodorize the evaporator case. For some of the vehicles specified below, a drilling procedure is identified in the deodorizing instructions. This type of alternative procedure and others can be done by using the referenced templates in the chart. 4. Complete detailed installation instructions are supplied with the blower control package. Important: A. 1996 ONLY (Use blower resistor location for drilling procedure) B. 1994-1996 ONLY Refer to appropriate Service Manual for enabling afterblow feature through on-board diagnostics. Parts Information Parts are currently available from GMSPO. Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6545 For vehicles repaired under warranty, use as shown. Figure 1 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6546 Figure 2 Figure 3 Figure 4 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6547 Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6548 Figure 7 Figure 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6549 Figure 9 Figure 10 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6550 Figure 11 Figure 12 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6551 Figure 13 Figure 14 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6552 Figure 15 Figure 16 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6553 Figure 17 Figure 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6554 Figure 19 Figure 20 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6555 Figure 21 Figure 22 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6556 Figure 23 Figure 24 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6557 Figure 25 Figure 26 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > Customer Interest: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6558 Figure 27 Figure 28 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System Evaporator Core: All Technical Service Bulletins A/C - Musty Odors Emitted From (HVAC) System TECHNICAL Bulletin No.: 99-01-39-004C Date: June 12, 2009 Subject: Air Conditioning Odor (Install Evaporator Core Dryer Kit and Apply Cooling Coil Coating) Models: 1993-2010 GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 All Equipped with Air Conditioning Supercede: This bulletin is being revised to add the 2009 and 2010 model years. Please discard Corporate Bulletin Number 99-01-39-004B (Section 01 - HVAC). Condition Some customers may comment about musty odors emitted from the Heating, Ventilation and Air Conditioning (HVAC) system at vehicle start-up in hot, humid conditions. Cause This condition may be caused by condensate build-up on the evaporator core, which does not evaporate by itself in high humidity conditions. The odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. There are several other possible sources of a musty odor in a vehicle. A common source is a water leak into the interior of the vehicle or foreign material in the HVAC air distribution system. Follow the procedures in SI for identifying and correcting water leaks and air inlet inspection. The procedure contained in this bulletin is only applicable if the odor source has been determined to be microbial growth on the evaporator core inside the HVAC module. Correction Many vehicles currently incorporate an afterblow function within the HVAC control module software. The afterblow feature, when enabled, employs the HVAC blower fan to dry the evaporator after vehicle shut down and this function will inhibit microbial growth. Technicians are to confirm that the customer concern is evaporator core odor and that the vehicle has the imbedded afterblow feature, as defined in the SI document for that specific vehicle model, model year and specific HVAC option. Refer to SI for enabling the afterblow function. Vehicles being delivered in areas prone to high humidity conditions may benefit from having the afterblow enabled calibration installed prior to any customer comment. Important If the vehicle is not factory equipped with the imbedded afterblow enable feature, it may be added with the Electronic Evaporator Dryer Module Kit (P/N 12497910 or AC Delco 15-5876). Important When installing the Electronic Evaporator Dryer Module, you MUST use the included electrical splice connectors to ensure a proper splice. Complete detailed installation instructions and self testing procedures are supplied with the kit. If necessary, the Electronic Evaporator Dryer Module may be installed underhood if it is protected from extreme heat and water splash areas. To immediately remove the evaporator core odor on all suspect vehicles, it is necessary to eliminate the microbial growth and prevent its re-occurrence. To accomplish this, perform the following procedure: Vehicle and Applicator Tool Preparation 1. The evaporator core must be dry. This may be accomplished by disabling the compressor and running the blower fan on the recirc heat setting for an extended period of time. Note Compressor engagement will cause the evaporator core to remain wet and will prevent full adherence of the Coiling Coil Coating to the evaporator core surfaces. 2. Verify that the air conditioning drain hose is not clogged and place a drain pan beneath the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 6564 3. Place a protective cover over the carpet below the evaporator core. 4. Remove the cabin air filter, if equipped, and cover the opening prior to applying the Cooling Coil Coating, as the product may clog the filter. If the cabin air filter appears to have little or no remaining life, suggest a replacement to your customer. 5. If the HVAC module has a blower motor cooling tube, be careful NOT TO SPRAY THE COOLING COIL COATING INTO THE BLOWER MOTOR COOLING TUBE. 6. Attach the Flexible Applicator Pressure Spray Tool (J-43810-20A) to a compressed air line operating at 586 kPa (85 psi) to 793 kPa (115 psi). 7. Shake the bottle of Cooling Coil Coating well. Screw the bottle onto the cap on the applicator tool's pick-up tube. Note The pick-up tube is designed for 120 ml (4 oz) and 240 ml (8 oz) bottles and should coil slightly in the bottom of a 120 ml (4 oz) bottle. 8. Use one of the following three methods to apply the Cooling Coil Coating. Important If the Pressure Applicator Spray Tool (J-43810-20A) is not available, the Cooling Coil Coating is also available in an aerosol can (P/N 12377951 (in Canada, 10953503)). Application Through Blower Motor Control Module Opening - Remove the blower motor control module (blower motor resistor). Refer to the applicable procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor blower motor control module (blower motor resistor) opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor blower motor control module (blower motor control module). Application Through Blower Motor Opening - Remove the blower motor. Refer to the applicable blower motor removal procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor. Application Through a Hole in the HVAC Module - If neither of the two previous application methods are available, it may be necessary to drill a hole in the HVAC module. - Locate an area of the HVAC module between the blower motor and the evaporator core. Drill a 10 mm (3/8 in) hole in the HVAC module. Use caution to keep the drill clear of the evaporator core and the blower motor fan. - With the air distribution vents closed and the blower motor fan speed on HIGH, insert the applicator tool into the hole and spray the Cooling Coil Coating into the airstream toward the evaporator core. - Use a GM approved RTV sealant to plug the hole in the HVAC module. 9. After the Cooling Coil Coating application is complete, start and run the vehicle for approximately 10 minutes, with the compressor disabled, HVAC mode set to Recirculate/Max, heat set to full warm, blower motor fan speed on high, and one window open approximately 12 mm (1/2 in). This cures the Cooling Coil Coating onto the evaporator core surface. 10. While the engine is running, rinse the applicator tool with warm water to prolong the life of the tool. Be sure to spray warm water through the nozzle to rinse out any residual Cooling Coil Coating still in the capillary pick up tube, otherwise it will dry and clog the applicator tool. Also remove the small green valve from the bottle cap and rinse it thoroughly while rolling it between two fingers and then reinstall it. If this valve is clogged , the Cooling Coil Coating will not flow through the applicator tool. 11. Shut off the engine and enable the compressor again. 12. Verify proper HVAC system operation. 13. Remove the protective cover from inside the vehicle. 14. Remove the drain pan from underneath the vehicle. 15. Reinstall the cabin air filter if necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 6565 Parts Information Important The Cooling Coil Coating listed below is the only GM approved product for use under warranty as an evaporator core disinfectant and for the long term control of evaporator core microbial growth. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates Evaporator Core: All Technical Service Bulletins A/C - Odor at Start up in Humid Climates File In Section: 1 - HVAC Bulletin No.: 53-12-12A Date: December, 1996 Subject: Air Conditioning Odor at Start Up in Humid Climates (Disinfect Evaporator Core, Install Delayed Blower Control Package) Models: 1993-96 Passenger Cars (Except GEO) 1993-96 Light Duty Models (Except Tracker) This bulletin is being revised to update the wiring diagrams, add the Corvette (with RPO C60) and delete medium/heavy duty trucks. Please discard Corporate Bulletin Number 53-12-12 (Section 1 HVAC). Condition Some owners may comment on odors emitted from the air conditioning system, primarily at start up in hot, humid climates. Cause This odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. Correction To remove odors of this type, it is necessary to eliminate the microbial growth and prevent its recurrence. To accomplish this, these two procedures must be completed. ^ Deodorize the evaporator core using Deodorizing Aerosol Kit, P/N 12377951 (AC Delco 15-102). ^ Install the new A/C Delayed Blower Control Package, P/N 12370470, (AC Delco 15-8632). The blower control package will enable the blower to run at high speed for five (5) minutes. It will do so approximately fifty (50) minutes after the ignition has been turned off if the compressor had been engaged for four (4) or more minutes prior to shutting off engine. By doing so, the evaporator case and core are dried out, reducing the chances of a recurring A/C odor. Procedure 1. Visually inspect the air conditioning evaporator drain hose for obstructions or working condition. 2. Apply deodorizing aerosol as described in the instructions supplied with the kit. Once the deodorizer has been applied, some of the mixture may overflow from the drain hose. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6570 3. The chart identifies specific instructions for each vehicle. This chart will identify the proper deodorizing procedure, template and wiring diagram. Deodorizing the evaporator case can easily be done by removing the blower motor resistor and tape off opening. The nozzle can now be inserted through a pierced hole in the tape to deodorize the evaporator case. For some of the vehicles specified below, a drilling procedure is identified in the deodorizing instructions. This type of alternative procedure and others can be done by using the referenced templates in the chart. 4. Complete detailed installation instructions are supplied with the blower control package. Important: A. 1996 ONLY (Use blower resistor location for drilling procedure) B. 1994-1996 ONLY Refer to appropriate Service Manual for enabling afterblow feature through on-board diagnostics. Parts Information Parts are currently available from GMSPO. Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6571 For vehicles repaired under warranty, use as shown. Figure 1 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6572 Figure 2 Figure 3 Figure 4 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6573 Figure 5 Figure 6 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6574 Figure 7 Figure 8 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6575 Figure 9 Figure 10 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6576 Figure 11 Figure 12 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6577 Figure 13 Figure 14 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6578 Figure 15 Figure 16 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6579 Figure 17 Figure 18 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6580 Figure 19 Figure 20 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6581 Figure 21 Figure 22 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6582 Figure 23 Figure 24 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6583 Figure 25 Figure 26 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 6584 Figure 27 Figure 28 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Technical Service Bulletins > All Other Service Bulletins for Evaporator Core: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt Retractor: All Technical Service Bulletins Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Service and Repair > Front Evaporator Core: Service and Repair Front Evaporator And Blower Module REMOVE OR DISCONNECT 1. Negative battery cable. 2. Discharge and recover refrigerant from the system. 3. Engine coolant. 4. Coolant recovery reservoir. 5. Windshield washer fluid reservoir. 6. Electrical connectors, as necessary. 7. Heater core inlet and outlet hoses. 8. Compressor and condenser hose from the accumulator. 9. Evaporator from the accumulator. 10. Relay bracket. 11. Evaporator tube from the evaporator. 12. Evaporator and blower module bolts and nuts. 13. Evaporator and blower module. ^ Separate case halves. 14. Evaporator core. INSTALL OR CONNECT 1. Evaporator core. Refer to Refrigerant Oil Distribution, if replacing the evaporator core. See: Specifications/Capacity Specifications 2. Evaporator and blower module. 3. Evaporator and blower module bolts and nuts. ^ Tighten bolts to 6 N.m (53 lbs. in.). ^ Tighten nuts to 7.5 N.m (66 lbs. in.). 4. Evaporator tube to the evaporator. 5. Heater core inlet and outlet hoses. 6. Evaporator to the accumulator. ^ Tighten evaporator to 41 N.m (30 lbs. ft.). 7. Compressor and condenser hose to the accumulator. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Service and Repair > Front > Page 6597 8. Relay bracket. 9. Electrical connectors, as necessary. 10. Windshield washer fluid reservoir. 11. Coolant recovery reservoir. 12. Engine coolant. 13. Negative battery cable. 14. Refrigerant to the system. ^ Check the system for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Evaporator Core > Component Information > Service and Repair > Front > Page 6598 Evaporator Core: Service and Repair Rear Rear Evaporator Module Assembly REMOVE OR DISCONNECT 1. Discharge and recover refrigerant from the system. 2. Auxiliary evaporator module cover. 3. Rear ducts. 4. Electrical connectors, as necessary. 5. Rear auxiliary evaporator tube assembly. 6. Screws. 7. Auxiliary evaporator module assembly. ^ Separate case halves. 8. Evaporator core seal. 9. Evaporator core. INSPECT ^ Gaskets and seals for damage; if damaged, replace. INSTALL OR CONNECT 1. Evaporator core. 2. Evaporator core seal. ^ Reassemble case halves. 3. Rear auxiliary evaporator module assembly. 4. Screws. ^ Tighten screws to 1.3 N.m (11 lbs. in.). 5. Rear auxiliary evaporator tube assembly. 6. Electrical connectors, as necessary. 7. Rear ducts. 8. Auxiliary evaporator module cover. 9. Refrigerant to the system. ^ Check the system for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Expansion Block/Orifice Tube > Component Information > Locations Expansion Block/Orifice Tube: Locations Evaporator Case-Expansion Tube The plastic expansion tube, with its mesh screen and orifice, is located in the liquid line between the condenser and the evaporator. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Expansion Block/Orifice Tube > Component Information > Locations > Page 6602 Expansion Block/Orifice Tube: Service and Repair Evaporator Tube Evaporator Case-Expansion Tube REMOVE OR DISCONNECT Tool Required: J 26549-E Orifice Tube Remover and Installer or Equivalent Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Expansion Block/Orifice Tube > Component Information > Locations > Page 6603 1. Discharge and recover refrigerant from the system. 2. Evaporator tube from the evaporator. 3. O-ring seal. 4. Expansion (orifice) tube using J 2654g-E. NOTE:If difficulty is encountered during the removal of a restricted or plugged expansion (orifice) tube, the following procedure is recommended: A. Remove as much of any impacted residue as possible. B. Carefully apply heat with heat gun (hair drier, epoxy drier, or equivalent) approximately 7mm (0.25 inch) from dimples on the inlet pipe. Do not overheat the pipe. CAUTION: If the system has a pressure switch near the expansion tube location, it should be removed prior to heating the pipe to avoid damage to the switch. C. While applying heat, use the expansion tube removal tools (J 2654g-E) or equivalent to grip the expansion (orifice) tube. Use a turning motion along with a push-pull motion to loosen the impacted expansion (orifice) tube and remove it. INSTALL OR CONNECT 1. Install the "shorter screen end" first into the evaporator. 2. New O-ring seal. ^ Coat O-ring seal with 525 viscosity refrigerant oil. 3. Evaporator tube to the evaporator. ^ Tighten tube to 24 N.m (18 lbs. ft.). 4. Refrigerant to the system. ^ Check the system for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Expansion Valve > Component Information > Locations Expansion Valve: Locations Rear Air Conditioning System Component View The Thermal Expansion Valve (TXV) is attached to the rear evaporator core, which is located in the left rear body trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Expansion Valve > Component Information > Locations > Page 6607 Expansion Valve: Service and Repair Figure 40-Rear Overhead System Component View REMOVE OR DISCONNECT 1. Evaporator core. 2. Gently remove the sealer packed around the Thermostatic Expansion Valve (TXV). 3. Clip retaining the capillary tube to the evaporator core. ^ Note the mounting location and orientation of the tube on the core. 4. Two nuts retaining the TXV to the evaporator core. 5. TXV from the core. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Expansion Valve > Component Information > Locations > Page 6608 INSTALL OR CONNECT 1. TXV to the core. 2. Nuts retaining the TXV to the evaporator core. 3. Capillary tube and retaining clip to the evaporator core. ^ Install the clip and tube in the location and orientation as noted during disassembly. 4. Pack sealer around TXV as found during disassembly. 5. Evaporator core. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Control Valve > Component Information > Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) Heater Control Valve: Diagrams Actuators and Control Schematic (With A/C) Control Assembly Operating Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6614 Schematic Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6615 Heater Control Valve: Diagrams Vacuum Harness Routing Vacuum Hose Routing, Engine Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Control Valve > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6616 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators Heater Core: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 6621 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 6622 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core Heater Core: Service and Repair Front Heater Core Removal Heater-Defroster Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6625 Heater Assembly Component View REMOVE OR DISCONNECT 1. Engine coolant. 2. Heater hoses. 3. Instrument panel lower filler. 4. Floor air outlet duct. 5. Outlet duct screws. 6. Windshield defrost outlet duct. 7. Case cover screws. 8. Heater case cover. 9. Heater core screws. 10. Heater core. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6626 11. Seals. Installation Heater-Defroster Assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6627 Heater Assembly Component View INSTALL OR CONNECT 1. Seals. 2. Heater core. 3. Heater core screws. 4. Heater case cover. 5. Case cover screws. 6. Windshield defrost outlet duct. 7. Outlet duct screws. ^ Tighten screws to 1.9 Nm (17 lb in). 8. Floor air outlet duct. 9. Instrument panel lower filler. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6628 10. Heater hoses. 11. Engine coolant. ^ Check the system for leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6629 Heater Core: Service and Repair Rear Removal Figure 20-Rear Heater Component View Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6630 Figure 21-Heater Wiring-Resistor Replacement REMOVE OR DISCONNECT 1. Coolant from the radiator. 2. Negative battery cable. 3. Clamps from the heater pipes. 4. Screws. 5. Cover. 6. Screws. 7. Strap. 8. Core. 9. Seals from the core. Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6631 Figure 20-Rear Heater Component View Figure 21-Heater Wiring-Resistor Replacement INSTALL OR CONNECT 1. Seals to the core. 2. Core. 3. Strap. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Core > Component Information > Service and Repair > Front Heater Core > Page 6632 4. Screws. 5. Cover. 6. Screws. 7. Pipes to the core. 8. Clamps to the heater pipes. 9. Negative battery cable. 10. Coolant in radiator. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Hose > Component Information > Locations > Heater Hose Routing Heater Hose: Locations Heater Hose Routing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 6637 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 6638 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 6639 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Heater Hose > Component Information > Locations > Heater Hose Routing > Page 6640 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 08-01-38-001 > Jan > 08 > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant > Page 6654 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment > Page 6659 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6664 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6665 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6666 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6667 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6668 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6669 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6670 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6671 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6672 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6673 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6674 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6675 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6676 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6677 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6678 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6679 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6680 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6681 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6682 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6683 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6684 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 6685 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations > Page 6690 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling Refrigerant: Technical Service Bulletins Contaminated R12 Refrigerant - Testing & Handling FILE IN SECTION: 1 - HVAC BULLETIN NO.: 53-12-05 DATE: May, 1995 SUBJECT: Contaminated R12 Refrigerant Testing and Handling MODELS: 1994 and Prior Passenger Cars and Trucks with R12 A/C Systems The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to perform normal A/C service procedures. Proper use of this tool can: ^ Prevent damage to your R12 recovery/recycling equipment. ^ Prevent contamination of previously recovered R12 in the recovery tank. ^ Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system. ^ Prevent the spread of contaminated R12 to other vehicles you service. If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for contamination prior to use. Sources of Contaminated R12 Refrigerant Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as other sources: ^ The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling. ^ Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers". ^ Poor quality or contaminated new or reprocessed R12 refrigerant. R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a refrigerant mixture which cannot be used in an A/C system. R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment to service each substitute refrigerant used. However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC (another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12 refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination of the R12 supply and the loss of the R12 recycling program. What To Do When Contamination is Detected Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant. Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 6695 contact or return to the previous repair facility. Explain that environmental regulations prohibit repair facilities from discharging ozone depleting A/C refrigerants into the atmosphere. Explain that recovery of this unknown refrigerant could damage your service equipment. If the customer wishes to pursue repairs through your facility, it is recommended that the proper A/C service equipment be purchased. General Motors recommends the Kent-Moore J 41428 "Scavenger", an air operated refrigerant recovery station, be used to remove unknown refrigerants. The air operated feature reduces the hazard of recovering potentially flammable refrigerants. Dealers should evaluate the need to purchase the equipment based on the number of contaminated vehicles they encounter. As an alternative to the initial purchase of a recovery only station, dealers should check locally for A/C specialty shops which may have the equipment to service substitute or contaminated refrigerants. They may be able to provide contaminated refrigerant recovery service to the dealer. The GM Service Technology Group has tested a recovery procedure where a 15 or 30 pound DOT approved refillable tank is fully evacuated then connected to a vehicle A/C system to recover the charge. Testing has shown that even when the recovery tank is cooled down in dry ice, the procedure does not guarantee the entire charge will be recovered. Since EPA regulations require full recovery of ozone depleting substances, GM does not recommend this procedure. Contaminated Refrigerant Disposal Although A/C refrigerant testing and disposal have not been a service practice in the mobile A/C industry, It has been common in the stationary A/C service industry for many years. Listed at the end of this bulletin are companies that provide refrigerant disposal service for the stationary A/C industry. Please be advised that GM has not independently evaluated these companies and is not in any way endorsing or promoting the use of these companies. Each of these companies has expressed an interest in providing refrigerant disposal service to GM dealers. In working with the stationary A/C industry, these companies typically receive large volumes of different refrigerants that have been mixed together. Unfortunately, because the volume of material returned by the mobile A/C industry will be in much smaller quantities, the cost of handling will be greater. To arrange for return of the refrigerant, simply call the company nearest you using the phone number listed below. The company will advise you on billing and shipping procedures. Disposal cost will vary between $3.00 and $5.00 per pound plus freight and handling. Shipping charges will vary by distance and location. In general, a 7 to 10 day turn-around time on the tank can be expected. The tank can be shipped via common carrier. Documents that your refrigerant has been properly disposed of will be sent to you with the return of your tank. As an alternative, many dealerships already have contracts in place with a disposal company who manages their hazardous wastes. In these cases, the disposal service may agree to handle containers of mixed refrigerants. Initially, the local disposal companies may be surprised by this inquiry. They may want to evaluate how much material will be collected before deciding whether to provide this service. As we move forward with the practice of testing R12 refrigerant, it will take time for all the questions to be answered. STG will provide additional information as soon as it is available. Understanding The PureGuard The PureGuard is a highly sensitive instrument capable of detecting R12 with 3% or less cross-contamination with other refrigerants. Any refrigerant mixture in excess of this amount poses a threat to both your refrigerant supply and recovery equipment. The PureGuard uses a pass/fail approach when monitoring the refrigerant and is precisely calibrated to cut power to the recovery machine if it encounters R12 mixed with any substitute refrigerants. The PureGuard ignores the presence of the air, dyes or oils in the refrigerant sampled. At least 20 psi must be present in the vehicle's A/C system for the PureGuard to function. Otherwise, refrigerant cannot be introduced to the PureGuard's test chamber. If a vehicle's A/C system contains less than 20 psi, it is an indication that the vehicle's system is nearly depleted of refrigerant. Occasionally, erratic PureGuard operation or service code 002 display will be encountered when A/C system pressure is exactly 20 psi. If this occurs, simply cycle the on/off switch to reset the PureGuard. After the 30 second PureGuard warm-up cycle, proceed immediately with vehicle recovery operation. Feedback from the field has indicated PureGuard service code 002 will also be displayed if the oil drain port is not sealed. Make sure the "0" ring seal in the cap is in place and that the cap is tight. If the PureGuard fails to clear or if you experience any other problems operating the PureGuard, contact Kent-Moore Technical Service at 1-800-345-2233. The unit should not be returned without first contacting Kent-Moore to obtain return authorization. Refrigerant Disposal Locations: United States Refrigerant Reclamation Inc. 12420 North Green River Rd. Evansville, IN 47711 800-207-5931, FAX - 812-867-1463 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 6696 Omega Refrigerant Reclamation 5263 North Fourth St. Irwindale, CA 91706 310-698-0991, FAX 310-696-1908 Refrigerant Management Svcs of Georgia 216 F. Atlanta Hwy. Cumming, GA 30130 Ph/FAX 800-347-5872 Refrigerant Reclaim Inc. 122 Old Stage Coach Rd. Dumfries, VA 22026 800-238-5902, FAX 703-441-0393 Gartech Refrigerant Reclamation Ctr. 2002 Platinum Garland, TX 75042 214-272-4070, FAX 214-272-8548 National Refrigerants, Inc. 11401 Roosevelt Blvd. Philadelphia, PA 19154 215-698-6620, FAX 215-602-8205 CFC Reclamation 1321 Swift North Kansas City, MO 64116 816-471-2511 Full Cycle-Global 550 James Street Lakewood, NJ 08701 908-370-3400, FAX - 908-370-3088 Refrigerant Reclaim Svcs, Inc. dba Full Cycle-Global 121 S. Norwood Drive Ft. Worth, TX 76053-7807 817-282-0022, FAX - 800-831-6182 Full Cycle-Global 2055 Silber, Ste. 109 Houston, TX 77055 713-681-7370, FAX - 713-681-9947 Full Cycle-Global 343 South Airline Hwy. Gonzales, LA 70737 504-644-5303, FAX - 504-644-1809 Full Cycle-Global 2966 Wireton Blue Island, IL 60406 708-388-8551, FAX - 708-388-8550 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye Refrigerant: Technical Service Bulletins A/C - R134a Leak Detection With Tracer Dye File In Section: 1 - HVAC Bulletin No.: 43-12-15 Date: November, 1994 Subject: R134a Leak Detection with Tracer Dye Models: All 1993-95 Vehicles with OEM R134a Systems All R12 Vehicles Retrofitted to R134a Systems R134a refrigerant is uniquely different from R12 refrigerant and requires some changes in the repair methods, tools and materials used in A/C service. Two important differences between R134a and R12 which affect the technicians ability to locate refrigerant leaks are: 1. The R134a molecule is smaller than the R12 molecule and therefore will leak through smaller openings. For the same size opening the smaller R134a molecule will leak out faster than the R12. 2. R134a refrigerant does not contain chlorine which the older R12 electronic leak detectors found very easy to identify. Many of today's electronic leak detectors have difficulty locating small R134a refrigerant leaks. In order to insure the highest quality in A/C system service, the J 39400 electronic leak detector was released as an essential tool for all GM dealers. This is the only refrigerant leak detector approved by GM for service on R134a vehicles. If maintained properly (Reference Bulletin No. 431218) and used in accordance with Service Manual procedures, the J 39400 will provide the most accurate and efficient method of locating R134a refrigerant leaks under most conditions. If the technician cannot find the leak with the J 39400 and the system is known to have lost charge, a new fluorescent leak tracer dye Kent-Moore* P/N J 41447, has been released that mixes with the R134a PAG oil. This dye is detectable through the use of an ultraviolet (black) light and glows yellow/green at the leak location (similar to using dye in engine leak detection). J 41447 IS THE ONLY APPROVED DYE BY GENERAL MOTORS. Not all R134a dyes are compatible with GM's PAG oil. Some dyes decrease the oil viscosity or chemically react with the oil. Use of alternate products may affect system reliability and cause premature compressor failure. Note: THIS DYE IS NOT TO BE USED IN R-12 SYSTEMS. Unlike mineral oil, the R134a PAG oil has special properties the technician should keep in mind. 1. PAG oil is water soluble and traces of PAG oil found at leaking joints are subject to "washing out". Condensation on refrigerant lines or the evaporator core may wash the PAG oil and leak dye off the line or off the core and out the condensate drain. This can make some leaks harder to find using the dye detector. Fluorescence at the drain opening would indicate a core leak. 2. Use of the R134a tracer dye requires time. Depending upon the leak rate, it may take between 15 minutes and 7 days for the leak to become visible. 3. The dye, mixed with the PAG oil, is retained in the system and is detectable for 2+ years. Do not double or triple charge the system with dye as this may cause reliability concerns. Use only the 1/4 oz. charge. The dye has a refrigerant leak detection notice sticker included with the package. Complete the sticker information and place near the charge label. Dye Injection R-134a dye can be injected two ways: 1. With the A/C system charged, use the instructions provided with the new R134a leak dye injection tool, J 41436. 2. With A/C system discharged, add dye into the newly replaced component assembly. It is important to note that it is normal to find oil traces at the compressor shaft seal during compressor operation, some oil will hydraulically seep past the shaft seal. This does not mean that the shaft seal is defective or that the refrigerant has leaked. Refrigerant leaks at the shaft seal should be verified with the electronic leak detector (J 39400) following the procedure detailed in the Service Manual. If, however, the amount of oil is excessive, the shaft seal is suspect and should be replaced. (For example, refrigerant oil has coated the clutch plate edge at gap between clutch and pulley, or oil slinging has occurred-oil line shows on underside of hood, etc.). Also, after working on A/C components with dye, it is important to wipe the joint and/or access ports clean of any residual dye with GM solvent (GM Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye > Page 6701 P/N 1050436) to prevent false diagnosis at a later point. * We believe this source and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Parts Information GM solvent, P/N 1050436, is currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431223 > Sep > 94 > A/C Refrigerant - Contamination Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431223 > Sep > 94 > A/C Refrigerant - Contamination > Page 6706 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A > Page 6711 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 922501A > Aug > 92 > A/C - Use of Alternate Refrigerants In CFC 12 Refrigerant: Technical Service Bulletins A/C - Use of Alternate Refrigerants In CFC 12 Number: 92-250-1A Section: 0A Date: AUGUST 1992 Corporate Bulletin No.: 231205 ASE No.: A7 Subject: USE OF ALTERNATE REFRIGERANTS IN CFC 12 REFRIGERANT MOBILE AIR CONDITIONERS Model and Year: GALL MODEL YEARS - ALL PASSENGER CARS AND TRUCKS INCLUDING GEO A number of inquiries have been received concerning the use of "alternate refrigerants" as a replacement for R-12 refrigerant in General Motors air conditioning systems. Regardless of any advertised claims, there are currently no substitutes for refrigerant R-12 approved by General Motors. At the present time, only new or recycled R-12 is approved for use in General Motors R-12 air conditioning systems. Based on studies performed to date, the use of "alternate refrigerants" in General Motors R-12 air conditioning systems may result in higher system pressures, higher leak rates or incompatibility with drying and sealing materials. System performance and reliability may also be affected. Service equipment manufacturers have indicated that cross-contaminating R-12 recovery/recycling equipment with "alternate refrigerants" may damage the equipment. General Motors supports the Society of Automotive Engineers recommended service procedures for recovery and recycling of R-12. The use of known "alternate refrigerants" without proper service practices for identifying vehicle systems containing these "alternate refrigerants" and dedicated recovery equipment to service those vehicles will contaminate the recycled supply of R-12 refrigerant. Contamination of the recycled R-12 refrigerant makes the refrigerant unusable for recharging air conditioning systems and could jeopardize the recycling program. At the present time, General Motors has not approved any "alternate refrigerant" for R-12 in R-12 air conditioning systems. Therefore, R-12 systems should continue to be serviced with new or recycled R-12 only. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 6716 Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 6717 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 6718 Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 6719 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 6720 Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 6721 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Specifications > Front Refrigerant: Specifications Front Refrigerant-134a Air Conditioning System ...................................................................................................................... .................................................... 0.91 kg (2.0 lb.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant > Component Information > Specifications > Front > Page 6724 Refrigerant: Specifications Rear Refrigerant-134a Front and Rear Air Conditioning System ................................................................................................................................................ 1.359 kg (3.0 lb.) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant Oil > Component Information > Technical Service Bulletins > A/C - New PAG Oil Refrigerant Oil: Technical Service Bulletins A/C - New PAG Oil Bulletin No.: 02-01-39-004B Date: November 16, 2005 INFORMATION Subject: New PAG Oil Released Models: 2006 and Prior GM Passenger Cars and Trucks (Including Saturn) 2003-2006 HUMMER H2 2006 HUMMER H3 2005-2006 Saab 9-7X Built With R-134a Refrigeration System All Air Conditioning Compressor Types (Excluding R4 and A6 Type Compressors) Supercede: This bulletin is being revised to change the PAG oil part number used for R4 and A6 compressors with R-134a refrigerant systems. Please discard Corporate Bulletin Number 02-01-39-004A (Section 01 - HVAC). All General Motors vehicles built with R-134a refrigerant systems shall now be serviced with GM Universal PAG Oil (excluding vehicles equipped with an R4 or A6 compressor). R4 and A6 compressors with R-134a refrigerant systems shall use PAG OIL, GM P/N 12356151 (A/C Delco part number 15-118) (in Canada, use P/N 10953486). Important: The PAG oil referenced in this bulletin is formulated with specific additive packages that meet General Motors specifications and use of another oil may void the A/C systems warranty. Use this new PAG oil when servicing the A/C system on the vehicles listed above. Oil packaged in an 8 oz tube should be installed using A/C Oil Injector, J 45037. Refer to the HVAC Section of Service Information for detailed information on Oil Balancing and Capacities. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant Oil > Component Information > Specifications > Capacity Specifications Refrigerant Oil: Capacity Specifications Front The Air Conditioning system requires 236 ml (8 fl. oz.) of Polyalkaline Glycol (PAG) refrigerant oil. New refrigerant oil must be added to the system when components are replaced, as follows: a. All Compressors (drain and measure the oil) ^ If less than 30 ml (1 fl. oz.) is drained add 60 ml (2 fl. oz.) to the new compressor. ^ If more than 30 ml (1 fl. oz.) is drained add same amount that was drained to the new compressor. b. Accumulator-Add 105 ml (3.5 fl. oz.) of new oil to the replacement accumulator to compensate for oil retained by original accumulator desiccant and bag assemblies. The accumulator should only be replaced if leaking due to a perforation, damaged O-ring seat, or damaged threads. c. Evaporator-Add 90 ml (3 fl. oz.) of new refrigerant oil. d. Condenser-Add 30 ml (1 fl. oz.) of new refrigerant oil. Rear The Air Conditioning system requires 298 ml (11 fl. oz.) of Polyalkaline Glycol (PAG) refrigerant oil. New refrigerant oil must be added to the system when components are replaced, as follows: a. All Compressors (drain and measure the oil) ^ If less than 30 ml (1 fl. oz.) is drained add 60 ml (2 fl. oz.) to the new compressor. ^ If more than 30 ml (1 fl. oz.) is drained add same amount that was drained to the new compressor. b. Accumulator-Add 105 ml (3.5 fl. oz.) of new oil to the replacement accumulator to compensate for oil retained by original accumulator desiccant and bag assemblies. The accumulator should only be replaced if leaking due to a perforation, damaged O-ring seat, or damaged threads. c. Evaporator-Add 90 ml (3 fl. oz.) of new refrigerant oil. d. Condenser-Add 30 ml (1 fl. oz.) of new refrigerant oil. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant Oil > Component Information > Specifications > Capacity Specifications > Page 6731 Refrigerant Oil: Fluid Type Specifications REFRIGERANT OIL TYPE ^ R-134a PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Evaporator Control Switch Refrigerant Pressure Sensor / Switch: Locations Evaporator Control Switch On multi use bracket, at RH side of cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Evaporator Control Switch > Page 6736 Refrigerant Pressure Sensor / Switch: Locations High Pressure Cutout Switch Back of A/C compressor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Page 6737 C166, Pressure Cycling Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations Blower Motor Relay: Locations Image updated by TSB 461103 Dated December 1994 Located on multi use bracket, at RH side of cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations > Page 6742 C164, HI A/C Blower Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Locations Blower Motor Switch: Locations Air Conditioning, Heater Control I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Locations > Page 6747 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Locations > Page 6748 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch C261, Auxiliary A/C Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 6751 C243, Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 6752 C243, Heater Blower Control Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Auxiliary A/C Blower Switch > Page 6753 C243, Heater Blower Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Evaporator Control Switch Refrigerant Pressure Sensor / Switch: Locations Evaporator Control Switch On multi use bracket, at RH side of cowl Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Evaporator Control Switch > Page 6758 Refrigerant Pressure Sensor / Switch: Locations High Pressure Cutout Switch Back of A/C compressor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations > Page 6759 C166, Pressure Cycling Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Service Port HVAC > Component Information > Locations Figure 1 B-5 Low and High Pressure Gage Fittings Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Locations > Vacuum Harness Routing Vacuum Harness HVAC: Locations Vacuum Harness Routing Vacuum Hose Routing, Engine Vacuum Harness, Dash Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Locations > Vacuum Harness Routing > Page 6767 Vacuum Harness HVAC: Locations Vacuum Hose Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Locations > Vacuum Harness Routing > Page 6768 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) Vacuum Harness HVAC: Diagrams Actuators and Control Schematic (With A/C) Control Assembly Operating Chart Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6771 Schematic Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6772 Vacuum Harness HVAC: Diagrams Vacuum Harness Routing Vacuum Hose Routing, Engine Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Heating and Air Conditioning > Vacuum Harness HVAC > Component Information > Diagrams > Actuators and Control Schematic (With A/C) > Page 6773 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 6780 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 6781 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure Air Bag: Technical Service Bulletins Air Bag - Module Shipping/Return Procedure File In Section: 9 - Accessories Bulletin No.: 31-90-04A Date: September, 1996 Subject: Supplemental Inflatable Restraint (SIR) Module Shipping/Return Procedure Models: 1993-97 Passenger Cars and Trucks - Equipped with Supplemental Inflatable Restraint (SIR) Modules EXCEPT THE MODELS AND YEARS AS LISTED This bulletin is being revised to update the: models and years affected, the contact telephone numbers and the hazardous classification rating. Various areas of the text and the attachments have also been revised. Please discard Corporate Bulletin Number 319004 (Group Reference Accessories). This bulletin outlines the return procedure for undeployed Supplemental Inflatable Restraint (SIR) modules. Undeployed SIR modules in all vehicles (except models indicated), removed for warranty purposes, are to be returned to Delphi Interior and Lighting Systems, General Motors Corporation. This bulletin outlines procedures that all dealers must follow for shipping undeployed airbag modules. This bulletin is in effect and should be retained at all times at the dealership until superseded by a subsequent bulletin. This return program does NOT apply to dealers in Alaska, Hawaii, US Territories, and foreign countries. SIR modules replaced outside the continental United States should be deployed and disposed of following the procedure outlined in Corporate Bulletin Number 319003R. All other modules (i.e., out of warranty or car scrapped) should be disposed of per Corporate Bulletin Number 319003R. Important: If a vehicle is the subject of a Preliminary Investigation (GM-1241), DO NOT ALTER the SIR system until cleared by the Zone Service Representative. An SIR module returned following a 1241 investigation must be clearly designated by: 1. Indicating on the REPAIR ORDER copy inside the box "SUBJECT TO 1241". 2. Indicating the VIN and vehicle owner on the REPAIR ORDER. 3. Sending photocopies of the REPAIR ORDER to: a. The appropriate Zone service Representative b. Cigna Company GM Central Claims Unit 485 W. Milwaukee Suite 690 Detroit, MI 48202 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6786 Mailing Address: P.O. Box 02489, Detroit, MI 48202 Questions related to handling of 1241 associated SIR modules may be answered by calling: Cigna Company - GM Central Claims Unit, 1-800-888-1491. The U.S. Department of Transportation (DOT) Hazardous Materials Regulations classify SIR modules as the following: ^ Proper Shipping Name: Air Bag Modules ^ Hazardous Class: Class 9 - Air Bag Failure to comply with DOT regulations will result in civil penalties of up to $10,000 per violation or criminal penalties of up to $25,000 per violation and imprisonment. Return Procedure for Supplemental Inflatable Restraint Modules (Undeployed Modules Only) All undeployed SIR modules in all vehicles (except as indicated in the models section of this bulletin), removed for warranty purposes, are to be returned to Delphi Interior and Lighting Systems, General Motors. The following procedure should be followed when returning SIR modules from any location within the continental United States. 1. Packaging Requirements Return undeployed SIR modules in the same carton that was received with the new replacement module. Do not use any carton that has been damaged to the extent that the product will not be protected during the shipment. If you need a replacement carton, contact Delphi Interior and Lighting Systems at (513) 356-2426. ENCLOSE A COPY OF THE REPAIR ORDER, detailing the reason(s) for the SIR module replacement. Close and secure the carton with packaging tape (transparent tape is recommended). All existing labels and markings on the carton must be visible. Important: DO NOT staple container. DO NOT cover any portion of the black and white "Class 9" label or any markings on the carton. 2. Package Labels and Markings Add the names and addresses for the consignee and the consignor. The method of closure cannot interfere with the labels or the markings on the package (see Attachments "A" - Driver Side, and "D" - Passenger Side). 3. Shipping Paper (UPS Hazardous Material Label and Shipper's Certification) The following items on the shipping papers must be completed with the same information as enclosed with the replacement SIR module when received: proper shipping name, hazard class, identification number, packaging group number, "EX" number, and emergency response telephone number. The remaining information should be completed in accordance with Attachments "B" and "E" (Driver Side) and "C" and "F" (Passenger Side). A copy of the emergency response guidelines (see Attachment "G") is enclosed with the replacement SIR module and must be attached to the shipping papers you complete for the SIR module being shipped. 4. Transportation All SIR modules are to be returned using United Parcel Service (UPS) which will require the sender to pre-pay the freight charges. If difficulties arise, contact Delphi Interior and Lighting Systems, General Motors at (513) 356-2426. 5. RETURN ALL SUPPLEMENTAL INFLATABLE RESTRAINT MODULES (EXCEPT FOR THOSE MODELS LISTED IN THIS BULLETIN) TO THE FOLLOWING ADDRESS: Delphi Interior and Light Systems 3249 McCall Avenue Dayton, OH 45417 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6787 ATTACHMENT A DRIVER AIRBAG Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6788 ATTACHMENT B DRIVER SIDE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6789 ATTACHMENT C DRIVER SIDE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6790 ATTACHMENT D PASSENGER AIRBAG Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6791 ATTACHMENT E PASSENGER SIDE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6792 ATTACHMENT F PASSENGER SIDE Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Air Bag - Module Shipping/Return Procedure > Page 6793 ATTACHMENT G Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Page 6794 Air Bag Assembly Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Technical Service Bulletins > Page 6795 Air Bag: Description and Operation The inflator module is located on the steering wheel hub. It consists of an inflatable bag and an inflator (gas canister). In the event of a frontal collision, current flows through the deployment loop, igniting the gas producing material in the inflator module and rapidly inflating the air bag. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Service and Repair > Driver's Inflator Module Air Bag: Service and Repair Driver's Inflator Module Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. Fig. 9 Inflator Module Replacement Removal 1. Remove inflator module mounting screws from back of steering column, Fig. 9. 2. Push down and twist horn contact lead counterclockwise, and remove from cam tower. 3. Remove Connector Position Assurance (CPA) retainer and disconnect air bag connector from inflator module. 4. Remove air bag inflator module from steering wheel. Installation 1. Connect air bag connector and Connector Position Assurance (CPA) retainer to inflator module. 2. Install air bag wires into channel in lower right portion of steering wheel. 3. Route horn contact lead through steering wheel and into cam tower and twist to right to locked position. 4. Install inflator module to steering wheel. Install top of module first to aid in assembly. 5. Install inflator module mounting screws through back of steering wheel and tighten to specifications. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag > Component Information > Service and Repair > Driver's Inflator Module > Page 6798 Air Bag: Service and Repair Passenger's Inflator Module Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Disconnect battery ground cable. 2. Remove passenger side knee bolster. 3. Disconnect connector position assurance and electrical connector. 4. Remove passenger inflator module pigtail connector from mounting hole in instrument panel. 5. Remove two inflator module to instrument panel carrier bolts. 6. Remove inflator module by sliding module rearward out from clips in instrument panel carrier, then tip module down and remove from vehicle. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag Control Module > Component Information > Locations > System Component Locations Fig. 2 Air Bag System Component Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag Control Module > Component Information > Locations > System Component Locations > Page 6803 Diagnostic Energy Reserve Module Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag Control Module > Component Information > Locations > Page 6804 C423, Resistor Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag Control Module > Component Information > Locations > Page 6805 Air Bag Control Module: Description and Operation A function of the DERM is to supply the deployment loop with a 36 volt loop reserve to ensure sufficient energy to deploy the air bag if the ignition feed to the arming sensor is lost during a frontal collision. Another function of the DERM is electrical system diagnostics. The DERM can detect circuit and component malfunctions within the deployment loop. Voltage drops across components within the loop are measured during non-deployment conditions. If the monitored voltages fall outside of the expected limits, the DERM will indicate a malfunction through the storage of a diagnostic trouble code and the illumination of the air bag warning light. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag Control Module > Component Information > Service and Repair > Diagnostic Energy Reserve Module (DERM) Air Bag Control Module: Service and Repair Diagnostic Energy Reserve Module (DERM) Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. Do not open DERM case for any reason. Touching connector pins or soldered components may cause electrostatic discharge damage. Repair of a malfunctioning DERM is by replacement only. 1. Remove DERM mounting bracket. 2. Remove connector position assurance lock, then disconnect DERM electrical connector. 3. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Air Bag Control Module > Component Information > Service and Repair > Diagnostic Energy Reserve Module (DERM) > Page 6808 Air Bag Control Module: Service and Repair Sensing and Diagnostic Module Replacement (SDM) Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Disconnect battery ground cable. 2. Remove left front seat. 3. Remove carpet retaining sill trim molding. 4. Fold back carpet to access SDM. 5. Disconnect connector assurance and electrical connector. 6. Remove SDM attaching nuts and SDM module. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Clockspring Assembly / Spiral Cable, Air Bag > Component Information > Description and Operation Clockspring Assembly / Spiral Cable: Description and Operation The coil assembly consists of two current carrying coils. They are attached to the steering column and allow rotation of the steering wheel while maintaining continuous contact of the deployment loop to the inflator module. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Clockspring Assembly / Spiral Cable, Air Bag > Component Information > Description and Operation > Page 6812 Clockspring Assembly / Spiral Cable: Service and Repair Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. SIR coil assembly will become uncentered if steering column is separated from steering gear and is allowed to rotate or centering spring is pushed down, letting hub rotate while coil assembly is removed from steering column. 1. Disconnect battery ground cable, then remove steering wheel as follows: a. Remove inflator module. b. Remove steering wheel nut, then disconnect horn lead assembly. c. Mark relationship of steering wheel to steering shaft, then remove steering wheel using steering wheel puller tool No. J-1859-03, or equivalent. Fig. 10 SIR Coil Assembly Removal 2. Remove coil assembly retaining ring, then the wave washer, Fig. 10. Fig. 11 Lock Bolt Guard Removal 3. With tilt steering, proceed as follows: a. Place ignition switch in Run position, then rotate steering shaft assembly until block tooth is at 7 o'clock position and bolt guard screws are accessible through wide slots in shaft lock, Fig. 11. b. Loosen screws on lock bolt guard until guard can be removed. Screws will be attached to lock bolt guard. c. Place ignition switch in Lock position. 4. Remove shaft lock retaining ring using lock plate compressor tool No. J-23653-SIR, or equivalent, to push down shaft lock. Discard ring. 5. Remove shaft lock, then the turn signal cancel cam. 6. Remove upper bearing spring, inner race seat and inner race. 7. Position turn signal lever in right turn (up) position, then remove multi-function switch as described under appropriate chassis chapter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Clockspring Assembly / Spiral Cable, Air Bag > Component Information > Description and Operation > Page 6813 Fig. 12 Turn Signal Switch Arm Removal 8. Remove round washer head screw and signal switch arm, then the oval head cross recess screw, Fig. 12. 9. Remove hazard warning button with hazard warning spring and hazard warning switch knob. 10. Remove binding head cross recess screws, then the turn signal switch assembly, noting the following: a. Let switch hang freely if removal is not necessary. b. Disconnect turn signal switch connector from connector body bracket and vehicle wire harness. c. Disconnect socket and bracket assembly connector terminal from slot "D" of turn signal switch connector. d. Remove connector body bracket, then the wiring protector. e. Gently pull wire harness through column. 11. Remove SIR coil assembly with wire harness from column assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Clockspring Assembly / Spiral Cable, Air Bag > Component Information > Description and Operation > Page 6814 Fig. 13 SIR Coil Assembly Centering Fig. 14 SIR Coil Assembly Wire Installation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Clockspring Assembly / Spiral Cable, Air Bag > Component Information > Description and Operation > Page 6815 Fig. 15 SIR Coil Assembly Alignment 12. Reverse procedure to install, noting the following: a. If coil assembly becomes uncentered, refer to Fig. 13. b. If installing new coil assembly, install pre-centered coil assembly to steering column, then remove and discard centering tab, Fig. 13. c. SIR coil assembly wire must be kept tight with no slack while installing SIR coil assembly, Fig. 14. Failure to do so may cause wire to be kinked near shaft lock area and cut when steering wheel is turned. d. Align opening in coil with horn tower and locating bump between two tabs on bracket and cover assembly, Fig. 15, then seat coil assembly into steering column. e. Turn signal control assembly must be in neutral position when assembling steering wheel. f. Do not misalign steering wheel more than 1 inch from horizontal centerline. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Diagnostic Connector, Air Bag > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Diagnostic Connector, Air Bag > Component Information > Locations > Page 6819 C297, Data Link Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module Arming Sensor Module Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module > Page 6824 Discriminating Sensors Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module > Page 6825 Discriminating Sensors Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Locations > Page 6826 C225A, Sensor Arming Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor Impact Sensor: Description and Operation Arming Sensor The arming sensor is a protective switch located in the power side of the deployment loop. It is calibrated to close at low level speed changes. This ensures that the inflator module is connected directly to the 36 Volt Loop Reserve (VLR) output of the DERM when either of the discriminating sensors close. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor > Page 6829 Impact Sensor: Description and Operation Discriminating Sensors There are two discriminating sensors in the air bag system. They are wired in parallel on the low (ground) side of the deployment loop. These sensors are calibrated to close with speed changes severe enough to warrant deployment. A diagnostic resistor is connected in parallel with the switch contacts within each of the discriminating sensors. These parallel resistors supply the ground path for the current passing through the deployment loop during normal operation. This current flow results in voltage drops across each component in the deployment loop. The DERM monitors these voltage drops to detect malfunctions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor Impact Sensor: Service and Repair Arming Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Raise and support vehicle. 2. Disconnect sensor electrical connector from retainer, remove Connector Position Assurance (CPA) lock from connector, then disconnect connector. 3. Remove sensor mounting bolts and sensor from vehicle. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor > Page 6832 Impact Sensor: Service and Repair Forward Discriminating Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Remove windshield washer reservoir. 2. Remove discriminating sensor electrical connector from retainer, then the Connector Position Assurance (CPA) lock from connector. 3. Disconnect sensor electrical connector. 4. Raise and support vehicle, then remove sensor harness from retainers. 5. Remove sensor bolts, then the sensors. 6. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Seat Occupant Sensor > Component Information > Technical Service Bulletins > Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Malfunction Lamp / Indicator, Air Bag > Component Information > Technical Service Bulletins > Customer Interest for Malfunction Lamp / Indicator: > 83-81-34 > Mar > 99 > SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: Customer Interest SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Malfunction Lamp / Indicator, Air Bag > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Malfunction Lamp / Indicator: > 83-81-34 > Mar > 99 > SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: All Technical Service Bulletins SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Air Bag Systems > Malfunction Lamp / Indicator, Air Bag > Component Information > Technical Service Bulletins > Page 6850 Malfunction Lamp / Indicator: Description and Operation The warning lamp will illuminate if there is an air bag system malfunction. Ignition voltage is supplied to the air bag warning lamp when the ignition switch is in the RUN or START positions. The DERM controls the lamp by providing a ground with the lamp driver. The air bag warning lamp will flash seven times when the ignition switch is first turned on to verify DERM operation. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Head Restraint System > System Information > Technical Service Bulletins > Restraints - Driver/Passenger Seat Head Rest Information Head Restraint System: Technical Service Bulletins Restraints - Driver/Passenger Seat Head Rest Information INFORMATION Bulletin No.: 10-08-50-003A Date: March 24, 2011 Subject: Information on Driver or Passenger Seat Head Restraint Concerns with Comfort, Custom Upholstery or Other Comfort Enhancing Devices Models: 2012 and Prior GM Passenger Cars and Trucks Equipped with Adjustable Head Restraints Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 10-08-50-003 (Section 08 - Body and Accessories). Important ON A GM VEHICLE EQUIPPED WITH ADJUSTABLE HEAD RESTRAINTS, USE THE HEAD RESTRAINT COVERS, FOAM AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER OR REPOSITION THE HEAD RESTRAINT SYSTEM. ANY ALTERATIONS TO HEAD RESTRAINTS DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER DESIGN ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. You may have a customer with a concern that the head restraint is uncomfortable or sits too far forward. The front driver and passenger seats are equipped with head restraints that have been designed to help minimize injuries while still providing comfort to the occupants. Each GM vehicle has its own specifically designed head restraint. The head restraints should only be used in the vehicle for which they were designed. The head restraint will not operate to its design intent if the original foam is replaced (1) by non-GM foam or head restraint, (2) by GM foam or head restraint designed for a different vehicle, (3) by GM foam or head restraint that has been altered by a trim shop or (4) if any object, such as an aftermarket comfort enhancing pad or device, is installed. Never modify the design of the head restraint or remove the head restraint from the vehicle as this may interfere with the operation of the seating and restraint systems and may prevent proper positioning of the passenger within the vehicle. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > System Component Locations Fig. 2 Air Bag System Component Locations Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > System Component Locations > Page 6860 Diagnostic Energy Reserve Module Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > Page 6861 C423, Resistor Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Locations > Page 6862 Air Bag Control Module: Description and Operation A function of the DERM is to supply the deployment loop with a 36 volt loop reserve to ensure sufficient energy to deploy the air bag if the ignition feed to the arming sensor is lost during a frontal collision. Another function of the DERM is electrical system diagnostics. The DERM can detect circuit and component malfunctions within the deployment loop. Voltage drops across components within the loop are measured during non-deployment conditions. If the monitored voltages fall outside of the expected limits, the DERM will indicate a malfunction through the storage of a diagnostic trouble code and the illumination of the air bag warning light. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Service and Repair > Diagnostic Energy Reserve Module (DERM) Air Bag Control Module: Service and Repair Diagnostic Energy Reserve Module (DERM) Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. Do not open DERM case for any reason. Touching connector pins or soldered components may cause electrostatic discharge damage. Repair of a malfunctioning DERM is by replacement only. 1. Remove DERM mounting bracket. 2. Remove connector position assurance lock, then disconnect DERM electrical connector. 3. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Service and Repair > Diagnostic Energy Reserve Module (DERM) > Page 6865 Air Bag Control Module: Service and Repair Sensing and Diagnostic Module Replacement (SDM) Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Disconnect battery ground cable. 2. Remove left front seat. 3. Remove carpet retaining sill trim molding. 4. Fold back carpet to access SDM. 5. Disconnect connector assurance and electrical connector. 6. Remove SDM attaching nuts and SDM module. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 6871 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Air Bag Systems/Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 6872 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Child Restraint > Child Seat Tether Attachment > Component Information > Technical Service Bulletins > Restraints - Child Seat Top Teather Attachment Kits Child Seat Tether Attachment: Technical Service Bulletins Restraints - Child Seat Top Teather Attachment Kits Bulletin No.: 99-09-40-004a Date: April 12, 2005 INFORMATION Subject: Top Tether Hardware Package for Child Restraint Seats Models: 1989-2002 Passenger Cars, Light Duty Trucks and Multi-Purpose Passenger Vehicles (Except EV1 and Prizm) Supercede: This bulletin is being revised to add the 2000-2002 model years. Please discard Corporate Bulletin Number 99-09-40-009 (Section 09 - Restraints). Important: GM of Canada and IPC Dealers are not authorized to utilize this service bulletin. Beginning in August, 1997 General Motors began providing Child Restraint Seat Top Tether Hardware Packages to customers in the United States who requested them. The Top Tether Hardware Package contains the necessary hardware for anchoring a forward facing child restraint seat top tether. One Child Restraint Seat Top Tether Hardware Package will be provided per vehicle to the retail customer at no charge for installation. Charges for installation of additional Top Tether Hardware Packages per vehicle are the responsibility of the customer. Most forward facing child restraint seats (CRS) sold in the United States prior to calendar year 1999 were not sold with top tether straps, but have provisions for them. Top tethers, which are required in Canada, can help to better secure the seat in the vehicle. When a forward facing CRS including a top tether is used, specially designed components must be used to secure the child seat top tether. These components are included in the Hardware Package from GMSPO. Top tethers are not normally required or used with rearward facing infant restraint seats. Rearward facing infant restraint seats should never be secured in the front seat of an air bag equipped vehicle unless the vehicle is equipped with an air bag de-activation (shut-off) switch and the switch has been used to turn the air bag off. Should a retail customer request installation of a Tether Hardware Package at the time of sale or delivery, it is to be installed at no charge to the owner. The labor to install a Tether Hardware Package prior to delivery of a new vehicle to the customer is considered to be part of the delivery "get ready process", and as such, is not claimable. Claiming for the cost and applicable handling allowance of the proper Tether Hardware Package used in the installation is allowed. If the customer requests installation of a Tether Hardware Package some time after delivery, the package is to be provided free of charge. Hardware Packages include installation instructions which are easily followed and can be installed by most customers. However, should the customer request the dealership's assistance to install the Tether Hardware Package, it is to be installed at no charge to the customer and the labor may be claimed. All claims submitted for installation labor of an approved Tether Hardware Package must be supported by a signed customer work order. Additional Hardware Packages and installation charges are the responsibility of the customer. In addition, passenger vehicle deliveries, including vans and sport utilities for daily rental usage, may have one tether hardware package supplied. Additional packages are the owner's responsibility. Dealers may claim appropriate parts under these circumstances. Sufficient quantities of parts should be ordered in advance of the arrival of vehicles to avoid delays. Important: When installing a Child Restraint Seat Top Tether Hardware Package, follow the installation instructions included in the package. Additional information about specific mounting locations and installations may be available in the Seat Belt Section (Sections 9, 10-10, 10-11 or 10A) I of the appropriate Service Manual, or the Restraints section of SI. Any questions regarding this policy should be directed to your Area Manager, Parts or Service. Parts Information For Top Tether Hardware Package part numbers and usage, see Group 14.870 (passenger cars & U-van), or Group 16.710 (Light Duty Truck) of the appropriate GMSPO Parts Catalog. In addition, they can also be found in Accessories Group 21.042. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Child Restraint > Child Seat Tether Attachment > Component Information > Technical Service Bulletins > Restraints - Child Seat Top Teather Attachment Kits > Page 6878 Warranty Information The dealership will be reimbursed for the parts and labor, if applicable, through the submission of a regular warranty claim. All claims submitted must be supported by a signed customer work order. Purchase and installation of additional Hardware Packages is the responsibility of the customer. For Top Tether Hardware Packages installed in the United States, submit as a normal warranty claim using the labor operations and time allowances shown. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt > Component Information > Technical Service Bulletins > Customer Interest for Seat Belt: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt: Customer Interest Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Belt: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt: All Technical Service Bulletins Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Buckle > Component Information > Technical Service Bulletins > Customer Interest for Seat Belt Buckle: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: Customer Interest Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Buckle > Component Information > Technical Service Bulletins > Customer Interest for Seat Belt Buckle: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues > Page 6900 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Buckle > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Belt Buckle: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: All Technical Service Bulletins Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Buckle > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Belt Buckle: > 09-09-40-001A > Feb > 11 > Restraints - Seat Belt Warning Lamp On/Buckling Issues > Page 6906 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Extension > Component Information > Technical Service Bulletins > Customer Interest: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt Extension: Customer Interest Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Extension > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Belt Extension: > 99-09-40-005F > Jun > 10 > Restraints - Extender Availability For Seat Belt Seat Belt Extension: All Technical Service Bulletins Restraints - Extender Availability For Seat Belt INFORMATION Bulletin No.: 99-09-40-005F Date: June 23, 2010 Subject: Seat Belt Extender Availability Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2009‐2011 model years and update the Warranty Information. Please discard Corporate Bulletin Number 99-09-40-005E (Section 09 Restraints). Important: DO NOT use belt extenders when securing a child restraint. The seat and shoulder belt restraint systems used in all General Motors vehicles have sufficient belt length to accommodate most drivers and passengers. Consequently, requests for belt extensions (extenders) should be minimal. Seat belt extenders are available ONLY IN BLACK for most GM passenger cars and trucks produced in recent years. They are available in two different lengths, 23 cm (9 in) and 38 cm (15 in). They are designed to be coupled with the existing belts in each vehicle. When in use, the extender makes the belt arrangement a "custom fit" and use by anyone else or in another vehicle will lessen or nullify the protection offered by the vehicle's restraint system. For this reason, it is extremely important that the correct length extender be used for the vehicle and occupant intended. Important: Do not use an extender just to make it easier to buckle the safety belt. Use an extender only when you cannot buckle the safety belt without using an extender. Parts Information For part numbers, usage and availability of extenders, see Extension Kit in Group 14.875 (cars) or Group 16.714 (trucks) of the appropriate parts catalog. Saturn retailers should refer to the appropriate model year Parts & Illustration catalog for the vehicle. U.S. Saab dealers should contact the Parts Help line. Canadian Saab dealers should fax requests to Partech Canada. Warranty Information ^ Seat belt extenders are a NO CHARGE item to all GM customers who request them for their specific vehicles. ^ Dealers should not be charging part costs since these extenders are supplied by GM to the dealers. ^ Dealers should not be charging labor costs since the extender can be customer installed. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Extension > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Belt Extension: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt Extension: All Technical Service Bulletins Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Extension > Component Information > Technical Service Bulletins > All Other Service Bulletins for Seat Belt Extension: > 99-09-40-005F > Jun > 10 > Restraints Extender Availability For Seat Belt Seat Belt Extension: All Technical Service Bulletins Restraints - Extender Availability For Seat Belt INFORMATION Bulletin No.: 99-09-40-005F Date: June 23, 2010 Subject: Seat Belt Extender Availability Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2009‐2011 model years and update the Warranty Information. Please discard Corporate Bulletin Number 99-09-40-005E (Section 09 Restraints). Important: DO NOT use belt extenders when securing a child restraint. The seat and shoulder belt restraint systems used in all General Motors vehicles have sufficient belt length to accommodate most drivers and passengers. Consequently, requests for belt extensions (extenders) should be minimal. Seat belt extenders are available ONLY IN BLACK for most GM passenger cars and trucks produced in recent years. They are available in two different lengths, 23 cm (9 in) and 38 cm (15 in). They are designed to be coupled with the existing belts in each vehicle. When in use, the extender makes the belt arrangement a "custom fit" and use by anyone else or in another vehicle will lessen or nullify the protection offered by the vehicle's restraint system. For this reason, it is extremely important that the correct length extender be used for the vehicle and occupant intended. Important: Do not use an extender just to make it easier to buckle the safety belt. Use an extender only when you cannot buckle the safety belt without using an extender. Parts Information For part numbers, usage and availability of extenders, see Extension Kit in Group 14.875 (cars) or Group 16.714 (trucks) of the appropriate parts catalog. Saturn retailers should refer to the appropriate model year Parts & Illustration catalog for the vehicle. U.S. Saab dealers should contact the Parts Help line. Canadian Saab dealers should fax requests to Partech Canada. Warranty Information ^ Seat belt extenders are a NO CHARGE item to all GM customers who request them for their specific vehicles. ^ Dealers should not be charging part costs since these extenders are supplied by GM to the dealers. ^ Dealers should not be charging labor costs since the extender can be customer installed. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Retractor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Belt Retractor: > 461603 > Aug > 94 > Seat Belt Extenders - Available to Relieve Discomfort Seat Belt Retractor: All Technical Service Bulletins Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Retractor > Component Information > Technical Service Bulletins > Customer Interest for Seat Belt Retractor: > 461603 > Aug > 94 > Seat Belt Extenders Available to Relieve Discomfort Seat Belt Retractor: Customer Interest Seat Belt Extenders - Available to Relieve Discomfort Group Ref.: 10 - Body Bulletin No.: 461603 Date: August, 1994 INFORMATION SUBJECT: SEAT BELT EXTENDERS MODELS: 1994 AND PRIOR CHEVROLET AND GMC TRUCK G/M/L VANS (INCLUDING RPO YF7 CONVERSION) THIS BULLETIN CANCELS AND REPLACES CORPORATE BULLETIN 261609. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CHEVROLET 92-183-10 GMC TRUCK 92-10A2-83 GM CANADA 92-2-260 Some owners of the above listed vehicles may comment that the seat belt or the lap shoulder belt does not provide a sufficient comfortable length. The seat belt extender offerings have been reduced to two for each truck platform (9 inches and 15 inches). Before ordering an extender, first determine that there is a physical requirement for the extender because the shortest length available is a 9 inch belt extender. If this length is not sufficiently long enough to allow the occupant to physically buckle the seat belt, then the longer 15 inch seat belt extender should be ordered. Use of the 15 inch extender should be limited to only those situations where it is absolutely required. It is important to emphasize the following to your customer: - The seat belt extender should not be used by anyone unless it is physically required in order to use the vehicle's safety belt system. - Use of an extender, where it is not physically required, significantly increases the potential for belt-induced abdominal injury in a severe crash. - Extenders MUST only be used in the specific seating position for the vehicle and occupant for which it was provided. The extender should be removed and stowed when not in use. - The seat belt extender MUST NOT be used if it causes the distance between the front edge of the buckle and the center of the occupant's body to be less than 6 inches. - Only one seat belt extender per seating position per request. - Seat belt extenders are provided at no cost to owners of these vehicles and the only available color is black. SERVICE PARTS INFORMATION P/N Description 12546204 Belt Extender 9 inches 12546205 Belt Extender 15 inches Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Retractor > Component Information > Technical Service Bulletins > Page 6942 Seat Belt Retractor: Locations In LH safety belt retractor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Belt Retractor > Component Information > Technical Service Bulletins > Page 6943 C396, Safety Belt Retractor Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Seat Belt Systems > Seat Sensor/Switch > Component Information > Locations Seat Sensor/Switch: Locations In LH safety belt retractor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module Arming Sensor Module Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module > Page 6952 Discriminating Sensors Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Arming Sensor Module > Page 6953 Discriminating Sensors Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Locations > Page 6954 C225A, Sensor Arming Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor Impact Sensor: Description and Operation Arming Sensor The arming sensor is a protective switch located in the power side of the deployment loop. It is calibrated to close at low level speed changes. This ensures that the inflator module is connected directly to the 36 Volt Loop Reserve (VLR) output of the DERM when either of the discriminating sensors close. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor > Page 6957 Impact Sensor: Description and Operation Discriminating Sensors There are two discriminating sensors in the air bag system. They are wired in parallel on the low (ground) side of the deployment loop. These sensors are calibrated to close with speed changes severe enough to warrant deployment. A diagnostic resistor is connected in parallel with the switch contacts within each of the discriminating sensors. These parallel resistors supply the ground path for the current passing through the deployment loop during normal operation. This current flow results in voltage drops across each component in the deployment loop. The DERM monitors these voltage drops to detect malfunctions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor Impact Sensor: Service and Repair Arming Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Raise and support vehicle. 2. Disconnect sensor electrical connector from retainer, remove Connector Position Assurance (CPA) lock from connector, then disconnect connector. 3. Remove sensor mounting bolts and sensor from vehicle. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor > Page 6960 Impact Sensor: Service and Repair Forward Discriminating Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Remove windshield washer reservoir. 2. Remove discriminating sensor electrical connector from retainer, then the Connector Position Assurance (CPA) lock from connector. 3. Disconnect sensor electrical connector. 4. Raise and support vehicle, then remove sensor harness from retainers. 5. Remove sensor bolts, then the sensors. 6. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Seat Occupant Sensor > Component Information > Technical Service Bulletins > Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Restraint Systems > Sensors and Switches - Restraint Systems > Seat Sensor/Switch > Component Information > Locations Seat Sensor/Switch: Locations In LH safety belt retractor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Antitheft and Alarm Systems > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > Customer Interest: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Keyless Entry Transmitter: Customer Interest Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Antitheft and Alarm Systems > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester Keyless Entry Transmitter: All Technical Service Bulletins Tools - Keyless Entry Transmitter Tester File In Section: 9 - Accessories Bulletin No.: 83-90-12 Date: August, 1998 INFORMATION Subject: Essential Tool J 43241 Remote Keyless Entry and Passive Keyless Entry Transmitter Tester Models: 1990-99 Passenger Cars and Trucks with Remote Keyless Entry or Passive Keyless Entry Systems A new essential tool, J 43241 Remote Keyless Entry Transmitter Tester, has been sent to all GM Dealers. This tester can be used on all RKE and PKE systems, on past as well as current models. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Antitheft and Alarm Systems > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester > Page 6984 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Antitheft and Alarm Systems > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Keyless Entry Transmitter: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Keyless Entry Transmitter: All Technical Service Bulletins Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Antitheft and Alarm Systems > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Other Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester Keyless Entry Transmitter: All Technical Service Bulletins Tools - Keyless Entry Transmitter Tester File In Section: 9 - Accessories Bulletin No.: 83-90-12 Date: August, 1998 INFORMATION Subject: Essential Tool J 43241 Remote Keyless Entry and Passive Keyless Entry Transmitter Tester Models: 1990-99 Passenger Cars and Trucks with Remote Keyless Entry or Passive Keyless Entry Systems A new essential tool, J 43241 Remote Keyless Entry Transmitter Tester, has been sent to all GM Dealers. This tester can be used on all RKE and PKE systems, on past as well as current models. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Antitheft and Alarm Systems > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Other Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester > Page 6994 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting Technical Service Bulletin # 83-96-05 Date: 980701 Radio Telephone/Mobile Radio - Install/Troubleshooting File In Section: 9 - Accessories Bulletin No.: 83-96-05 Date: July, 1998 Subject: Radio Telephone/Mobile Radio (Transceiver) Installation and Troubleshooting Guidelines Models: 1990-99 Passenger Cars and Trucks This bulletin cancels and supercedes bulletin 34-92-12. Please discard Corporate Bulletin Number 34-92-12 (Section 9 - Accessories). The following information is being provided to assist in the installation and troubleshooting of Radio Telephone/Mobile Radios. Certain radio telephones or land mobile radios (also known as Radio Transceivers), or the way in which they are installed, may adversely affect various vehicle operations such as engine performance, driver information, entertainment and electrical systems. Expenses incurred to protect the vehicle systems from any adverse effect of any such installation are NOT the responsibility of General Motors Corporation. The following are general guidelines for installing a radio transceiver in General Motors vehicles. These guidelines are intended to supplement, but not to be used in place of, detailed instructions which are the sole responsibility of the manufacturer of the involved radio transceiver. Although this document refers to passenger vehicles, the same general guidelines apply to trucks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting > Page 6999 EMC TROUBLESHOOTING CHART 1. Transceiver Location Refer to the attached figures during installation. 1. Transceiver Location Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting > Page 7000 a. One piece transceivers should be mounted under the dash, or on the transmission hump where they will not interfere with vehicle controls or passenger movement (See Figure 1 - One Piece Transceiver Installation). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting > Page 7001 b. Locate the transceiver for remote radios on the driver's side of trunk as near to the vehicle body side as possible (See Figure 2 - Trunk Mount Transceiver Installation). Caution: To avoid possible serious injury, do not mount any transceivers, microphones, speakers, or any other item In the deployment path of a Supplemental Inflatable Restraint (SIR) or "Air Bag". 2. Antenna Installation a. Each vehicle model reacts to radio frequency energy differently. It is suggested that a magnetic-mount antenna be used to check the proposed antenna location for unwanted effects on the vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting > Page 7002 Antenna location is a major factor in these effects. b. The antenna should be a permanent-mount type, located in the center of the roof or center of the rear deck lid. If a magnet-mount antenna is used, care should be taken to mount the antenna in the same location as a permanent-mount type. If a disguise-mount antenna is used, great care should be taken to shield (using copper tape, etc.) any tuning network from vehicle electronics and wiring, or mount the tuning network in an area completely clear (6 inches or 15 cm away) of vehicle electronics and wiring. c. Standard metal mount antennas may be mounted on a vehicle with non-metallic body panels by two methods: 1. Mount the antenna near a metal frame section and bond the antenna mount to the frame with a short metal strap, which will provide the ground plane connection. 2. Some antenna manufacturers may offer "Ground Plane Kits" that consist of self adhesive metal foil that may be attached to the body panel to provide a ground plane connection. d. Glass Mount Antennas Glass mounted antennas should be kept as high as possible in the center of the rear window or windshield, between rear window defrost "grid lines", if present. Some vehicles use glass that contains a thin metallic layer for defrosting, or to control solar gain. GLASS MOUNT ANTENNAS WILL NOT FUNCTION WHEN MOUNTED ON THIS TYPE OF GLASS. 3. Antenna Cable Routing a. Always use high quality coax cable (95% shield coverage minimum), located away (at least 6 inches or 15 cm) from ECM's, PCM's and other electronic modules. b. Care should be taken to maintain as great a distance as possible between any vehicle wiring and coax cable. 4. Antenna Tuning It is important that the antenna be tuned properly and that reflected power be kept to less than 10% (VSWR less than 2:1) at all operating frequencies. Important: High VSWR has been shown to contribute/cause interference problems with vehicle systems. 5. Radio Wiring and Power Lead Connection Locations a. Methods to connect radio power on General Motors vehicles is dependent on the vehicle model (See Figure 1 - One Piece Transceiver Installation or Figure 2 - Trunk Mount Transceiver Installation as needed). Do not connect the negative power lead to any under-dash termination point. One of the following four methods is suggested: 1. Connect the positive and negative power leads directly to the battery terminals. GM approved methods of connecting auxiliary wiring include the adapter package illustrated in Figure 4 - Power Cable Battery Connections. Important: It is recommended that a fuse be placed in the transceiver negative power lead. This is to prevent possible transceiver damage in the event the battery to engine block ground lead is inadvertently disconnected. 2. Connect the positive lead to the auxiliary power terminal (usually identified by a red plastic cover in the underhood area). Connect the negative lead directly to the negative battery terminal. Important: See above important statement regarding fusing the negative power lead. 3. Connect the positive lead to the auxiliary power terminal (usually identified by a red plastic cover in the underhood area). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting > Page 7003 Connect the negative lead to the battery body connection point (usually identified by a short # 10 AWG or larger wire running from the negative battery terminal to the body of the vehicle). Important: See above important statement regarding fusing the negative power lead. 4. Connect the positive and negative leads to the Special Equipment Option (SEO) wiring provided for this purpose (if vehicle has this option). b. For One Piece Transceivers (See Figure 1 - One Piece Transceiver Installation) When ignition switch control is desired, and no SEO wiring exists, a 12 volt power contactor must be installed in the transceiver positive power lead (See Figure 3 - Power Contactor Wiring). The contactor (supplied by the installer) should be located near a proper 12 volt feed source. One lead of the contactor coil should be connected through an appropriate in-line fuse to an available accessory circuit or ignition circuit not Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Cellular Phone > Component Information > Technical Service Bulletins > Radio Telephone/Mobile Radio - Install/Troubleshooting > Page 7004 powered during engine cranking. The return lead of the contactor coil must return to a proper fused negative point. c. Handset or Control Units 1. Any negative power lead from a handset or control unit must return to a properly fused negative connection point. 2. It is preferable that the positive power lead for a handset, or control unit, be connected directly to a properly fused positive power feed point. If ignition switch control is desired, the handset or control unit positive power lead may be connected through an appropriate in-line fuse to an available accessory circuit (or ignition circuit not powered during engine cranking). 3. It is recommended that the handset or control unit positive and negative power leads be appropriately fused separately from the transceiver positive and negative power leads. d. Multiple Transceivers or Receivers If multiple transceivers or receivers are to be installed in the vehicle, power leads to the trunk or under the dash should be connected to covered, insulated terminal strips. All transceivers or receivers may then have their power leads connected to the insulated terminal strips. This makes a neater installation and reduces the number of wires running to the vehicle underhood area. Both positive and negative power leads should be fused. 6. Radio Wire Routing (See Figure 1 - One Piece Transceiver Installation, or Figure 2 - Trunk Mount Transceiver Installation as needed). a. The power leads (fused) should be brought through a grommeted hole (provided by the installer) in the front cowl. For trunk mounted transceivers, the cables should continue on along the driver's side door sills, under the rear seat and into the trunk through a rear bulkhead. Maintain as great a distance as possible between radio power leads and vehicle electronic modules and wiring. b. If the radio power leads need to cross the engine compartment, they should cross between the engine and the front of the vehicle. Troubleshooting Refer to the Troubleshooting Chart as needed. 1. Most vehicle-radio interaction is avoided by following the Installation Guidelines outlined above. 2. If vehicle-radio interaction is evident following radio installation, the source of the problem should be determined prior to further vehicle/radio operation. The EMC Troubleshooting Chart should help in determining the source of the vehicle-radio interaction. Parts Information P/N Description 1846855 Adapter Kit, Side Terminal Battery (consisting of Adapter Terminal, Terminal Cover, Wire Connector, Insulation Boot) 12004188 Bolt, Battery Cable Terminal 12354951 Spacer, Battery Cable Terminal Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Technical Service Bulletins > Customer Interest for Compact Disc Player (CD): > 649601 > Jan > 97 > Compact Disc Players - CD Changer Loading Procedures Compact Disc Player (CD): Customer Interest Compact Disc Players - CD Changer Loading Procedures File In Section: 9 - Accessories Bulletin No.: 64-96-01 Date: January, 1997 INFORMATION Subject: Compact Disc Players - Procedures for Correct Use and Maintenance Models: 1997 and Prior Passenger Cars and Trucks CD Changer Loading Procedures Because of differences in CD changer loading procedures, some confusion exists regarding this issue. Although correct loading procedures are included with each changer's Owner's Manual, often this information is not available to the dealer service personnel. Verify proper loading when evaluating customer concerns of "CD inoperative". Delco Electronics Product Type Loading Procedure Radio w/intergral CD label side up 6 disc changer (LLAI) label side up 10 disc changer (FMI) label side up 12 disc changer (LLAI) label side down Important: Failure to load magazine/player correctly will disable the operation. Important: Only the 12 disc changer is to be loaded with the label side down. CD Cleaners Avoid use of commercially available CD cleaners. The use of CD cleaners is not recommended and can damage the player's CD mechanism. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Compact Disc Player (CD): > 649601 > Jan > 97 > Compact Disc Players - CD Changer Loading Procedures Compact Disc Player (CD): All Technical Service Bulletins Compact Disc Players - CD Changer Loading Procedures File In Section: 9 - Accessories Bulletin No.: 64-96-01 Date: January, 1997 INFORMATION Subject: Compact Disc Players - Procedures for Correct Use and Maintenance Models: 1997 and Prior Passenger Cars and Trucks CD Changer Loading Procedures Because of differences in CD changer loading procedures, some confusion exists regarding this issue. Although correct loading procedures are included with each changer's Owner's Manual, often this information is not available to the dealer service personnel. Verify proper loading when evaluating customer concerns of "CD inoperative". Delco Electronics Product Type Loading Procedure Radio w/intergral CD label side up 6 disc changer (LLAI) label side up 10 disc changer (FMI) label side up 12 disc changer (LLAI) label side down Important: Failure to load magazine/player correctly will disable the operation. Important: Only the 12 disc changer is to be loaded with the label side down. CD Cleaners Avoid use of commercially available CD cleaners. The use of CD cleaners is not recommended and can damage the player's CD mechanism. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions Compact Disc Player (CD): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7021 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7022 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7023 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7024 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7025 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7026 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7027 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7028 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7029 Compact Disc Player (CD): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7030 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7031 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7032 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7033 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7034 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7035 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7036 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7037 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7038 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7039 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7040 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7041 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7042 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7043 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7044 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7045 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7046 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7047 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7048 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7049 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7050 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Compact Disc Player (CD) > Component Information > Diagrams > Diagram Information and Instructions > Page 7051 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Radio/Stereo > Radio/Stereo Noise Filter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Radio/Stereo Noise Filter: > 449601 > Apr > 94 > Radio - Buzzing Noise in AM Band With Engine Running Radio/Stereo Noise Filter: All Technical Service Bulletins Radio - Buzzing Noise in AM Band With Engine Running Group Ref.: Accessories Bulletin No.: 449601 Date: April, 1994 SUBJECT: BUZZING NOISE IN AM BAND OF RADIO (INSTALL FILTER ON PCM/TCM) MODELS: 1992-94 CHEVROLET AND GMC TRUCK C/K, S/T TRUCKS AND M/L, G VANS 1992-94 OLDSMOBILE BRAVADA WITH 4L60-E AND 4L80-E TRANSMISSIONS CONDITION: Some owners may comment of a buzzing noise in the low end of the AM radio band with the engine running. CAUSE: The switching of the force motor in the electronic transmission emits an RFI signal through the PCM/TCM. The AM band of the radio is receiving this interference through the antenna. CORRECTION; To determine if this is the cause of the owner's comments. first duplicate the condition and then disconnect the electrical connector at the transmission (this will disable the force motor). If the condition improves. install an in-line filter (P/N 1224205) to the ignition lead (ckt 439) of the PCM/TCM. Some applications may have two (439 ckt), in which case, a filter will be required for each lead. NOTE: Disconnecting the electrical connector at the transmission will set the transmission diagnostic codes. It will be necessary to remove these codes after the corrective action has been performed. IMPORTANT: Discard the instructions in the filter package. This filter Is an in-line filter with a single lead on one end and two leads on the other end (one lead being black (ground). Install this filter as close to the PCM/TCM connector as possible. It Is important to Install the filter with the single lead end going toward the PCM/TCM and then take the black (ground) lead back and attach it to the case of the PCM/TCM. If this filter is installed incorrectly, the condition will become worse. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Radio/Stereo > Radio/Stereo Noise Filter > Component Information > Technical Service Bulletins > Customer Interest for Radio/Stereo Noise Filter: > 449601 > Apr > 94 > Radio - Buzzing Noise in AM Band With Engine Running Radio/Stereo Noise Filter: Customer Interest Radio - Buzzing Noise in AM Band With Engine Running Group Ref.: Accessories Bulletin No.: 449601 Date: April, 1994 SUBJECT: BUZZING NOISE IN AM BAND OF RADIO (INSTALL FILTER ON PCM/TCM) MODELS: 1992-94 CHEVROLET AND GMC TRUCK C/K, S/T TRUCKS AND M/L, G VANS 1992-94 OLDSMOBILE BRAVADA WITH 4L60-E AND 4L80-E TRANSMISSIONS CONDITION: Some owners may comment of a buzzing noise in the low end of the AM radio band with the engine running. CAUSE: The switching of the force motor in the electronic transmission emits an RFI signal through the PCM/TCM. The AM band of the radio is receiving this interference through the antenna. CORRECTION; To determine if this is the cause of the owner's comments. first duplicate the condition and then disconnect the electrical connector at the transmission (this will disable the force motor). If the condition improves. install an in-line filter (P/N 1224205) to the ignition lead (ckt 439) of the PCM/TCM. Some applications may have two (439 ckt), in which case, a filter will be required for each lead. NOTE: Disconnecting the electrical connector at the transmission will set the transmission diagnostic codes. It will be necessary to remove these codes after the corrective action has been performed. IMPORTANT: Discard the instructions in the filter package. This filter Is an in-line filter with a single lead on one end and two leads on the other end (one lead being black (ground). Install this filter as close to the PCM/TCM connector as possible. It Is important to Install the filter with the single lead end going toward the PCM/TCM and then take the black (ground) lead back and attach it to the case of the PCM/TCM. If this filter is installed incorrectly, the condition will become worse. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH Speaker: Locations Indoor LH Door Wiring, LH Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH > Page 7070 Rear Speaker Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH > Page 7071 Rear Speaker Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH > Page 7072 Speaker: Locations Speaker Front Speaker Wiring Front Speaker Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH > Page 7073 Speaker: Locations Upper LH Door Wiring, LH Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH > Page 7074 Rear Speaker Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Locations > Indoor LH > Page 7075 Rear Speaker Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions Speaker: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7078 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7079 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7080 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7081 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7082 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7083 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7084 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7085 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7086 Speaker: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7087 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7088 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7089 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7090 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7091 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7092 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7093 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7094 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7095 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7096 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7097 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7098 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7099 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7100 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7101 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7102 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7103 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7104 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7105 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7106 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7107 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7108 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7109 Speaker: Connector Views C230, Rear Speaker Extension C230, Rear Speaker Extension C409, RH Rear Speaker Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7110 C408, LH Rear Speaker C901, LH Rear Indoor Speaker C903, RH Rear Indoor Speaker Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Speaker > Component Information > Diagrams > Diagram Information and Instructions > Page 7111 C221, LH Front Speaker C222, RH Front Speaker Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions Tape Player: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7116 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7117 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7118 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7119 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7120 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7121 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7122 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7123 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7124 Tape Player: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7125 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7126 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7127 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7128 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7129 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7130 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7131 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7132 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7133 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7134 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7135 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7136 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7137 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7138 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7139 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7140 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7141 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7142 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7143 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7144 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7145 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Radio, Stereo, and Compact Disc > Tape Player > Component Information > Diagrams > Diagram Information and Instructions > Page 7146 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7156 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7157 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7158 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7164 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7165 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7166 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7175 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7176 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 7177 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical MIL ON/DTC's Set By Various Control Modules > Page 7183 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical MIL ON/DTC's Set By Various Control Modules > Page 7184 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical MIL ON/DTC's Set By Various Control Modules > Page 7185 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Locations Trailer Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions Trailer Connector: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7192 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7193 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7194 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7195 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7196 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7197 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7198 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7199 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7200 Trailer Connector: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7201 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7202 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7203 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7204 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7205 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7206 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7207 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7208 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7209 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7210 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7211 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7212 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7213 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7214 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7215 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7216 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7217 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7218 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7219 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7220 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7221 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7222 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7223 Trailer Connector: Electrical Diagrams Trailer Tow (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7224 Trailer Tow (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Page 7225 Trailer Connector: Description and Operation The trailer lamps operate in the same manner as the vehicle lamps. The trailer lamps are grounded to the vehicle at G401 through the BLK (151) and WHT (22) ground wires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Towing / Trailer System > Trailer Connector > Component Information > Diagrams > Page 7226 Trailer Connector: Testing and Inspection The trailer lamps operate in the same manner as the vehicle lamps. The trailer lamps are grounded to the vehicle at G401 through the BLK (151) and WHT (22) ground wires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Locations Trailer Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions Trailer Connector: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7232 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7233 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7234 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7235 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7236 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7237 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7238 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7239 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7240 Trailer Connector: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7241 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7242 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7243 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7244 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7245 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7246 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7247 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7248 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7249 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7250 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7251 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7252 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7253 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7254 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7255 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7256 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7257 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7258 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7259 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7260 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7261 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7262 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7263 Trailer Connector: Electrical Diagrams Trailer Tow (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Diagram Information and Instructions > Page 7264 Trailer Tow (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Page 7265 Trailer Connector: Description and Operation The trailer lamps operate in the same manner as the vehicle lamps. The trailer lamps are grounded to the vehicle at G401 through the BLK (151) and WHT (22) ground wires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Accessories and Optional Equipment > Trailer Connector > Component Information > Diagrams > Page 7266 Trailer Connector: Testing and Inspection The trailer lamps operate in the same manner as the vehicle lamps. The trailer lamps are grounded to the vehicle at G401 through the BLK (151) and WHT (22) ground wires. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Bumper > Front Bumper > Front Bumper Cover / Fascia > System Information > Technical Service Bulletins > Body - TPO Fascia Cleaning Prior to Painting Front Bumper Cover / Fascia: Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Bumper > Front Bumper > Front Bumper Reinforcement > System Information > Technical Service Bulletins > Body - Polypropylene Energy Absorber Replacement Front Bumper Reinforcement: Technical Service Bulletins Body - Polypropylene Energy Absorber Replacement Bulletin No.: 07-08-63-001 Date: April 17, 2007 INFORMATION Subject: Information on Repair of Polypropylene Energy Absorbers Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to change the repair information. Please discard Corporate Bulletin Number 63-20-02 (Section 8 - Body and Accessories). Because the energy absorbers are relatively low in cost to replace, it is now more cost efficient to replace the energy absorbers whenever they are damaged. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Bumper > Rear Bumper > Rear Bumper Cover / Fascia > System Information > Technical Service Bulletins > Body - TPO Fascia Cleaning Prior to Painting Rear Bumper Cover / Fascia: Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Bumper > Rear Bumper > Rear Bumper Reinforcement > System Information > Technical Service Bulletins > Body - Polypropylene Energy Absorber Replacement Rear Bumper Reinforcement: Technical Service Bulletins Body - Polypropylene Energy Absorber Replacement Bulletin No.: 07-08-63-001 Date: April 17, 2007 INFORMATION Subject: Information on Repair of Polypropylene Energy Absorbers Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to change the repair information. Please discard Corporate Bulletin Number 63-20-02 (Section 8 - Body and Accessories). Because the energy absorbers are relatively low in cost to replace, it is now more cost efficient to replace the energy absorbers whenever they are damaged. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Cowl > Component Information > Locations Cowl: Locations Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Cowl > Component Information > Locations > Page 7290 Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Handle > Front Door Handle Switch > System Information > Locations Liftgate Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Latch > System Information > Service and Repair Front Door Latch: Service and Repair Remove or Disconnect 1. Door trim panel. 2. Outside handle to lock assembly rod. 3. Lock cylinder to lock assembly rod. 4. Inside handle to lock assembly rod. 5. Inside lock to lock assembly rod. 6. Lock assembly screws. 7. Lock assembly from the door. Install or Connect 1. Lock assembly to the door. 2. Lock assembly screws. 3. Inside lock to lock assembly rod. 4. Inside handle to lock assembly rod. 5. Lock cylinder to lock assembly rod. 6. Handle to lock assembly rod. 7. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Panel > System Information > Locations Center High Mounted Stoplamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Panel > System Information > Service and Repair > Armrest Bracket Front Door Panel: Service and Repair Armrest Bracket Remove or Disconnect 1. Trim panel. Refer to Trim Panel. 2. Four rivets. ^ Use a 6-mm (1/4-inch) drill bit to remove the head from the rivet. 3. Arm rest bracket. 4. Water deflector. ^ Peel the water deflector away from the door, using a soft-faced scraper if necessary, to separate the deflector from the door. Install or Connect 1. Water deflector. 2. Armrest bracket to the door. 3. 6-mm (1/4-inch) rivets to the door. 4. Trim panel. Refer to Trim Panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Panel > System Information > Service and Repair > Armrest Bracket > Page 7306 Front Door Panel: Service and Repair Door Trim Panel Replacement Assist Handle Cover Front Door Trim Panel Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Panel > System Information > Service and Repair > Armrest Bracket > Page 7307 Hinge Components Remove or Disconnect Tool Required: J 09886-01 Door Handle Clip Remover and J 38778 Trim Pad and Garnish Clip Remover. 1. Two screws and armrest cover. ^ Slide the armrest cover toward the rear of the door. 2. Window handle using J 09886-01 (if equipped). 3. Assist handle cover using J 38778. A. Pry the cover from the door near the clips. B. Switch connectors (if equipped). 4. Screw from behind the armrest pad. 5. Trim panel retainers from the door using J 38778. 6. Trim panel from the door. Install or Connect NOTICE: For steps 3 and 6. When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused, and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above conditions are not followed, parts or system damage could result. 1. Trim panel retainers to the trim panel. 2. Trim panel to the door. ^ Place the window seal portion of the panel over the door frame. 3. Screw behind the armrest pad. Tighten: Trim panel screw to 1.9 Nm (17 lbs. in.). 4. Assist handle cover to the door. ^ Electrical connectors (if equipped). 5. Window handle (if equipped). 6. Armrest with screws. ^ Insert the tabs into the slots and push the armrest toward the front of the door. Tighten: Armrest screws to 1.9 Nm (17 lbs. in.). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Window Glass > System Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information Front Door Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Window Glass > System Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information > Page 7312 Front Door Window Glass: Technical Service Bulletins Body - Side Window Chipping Information INFORMATION Bulletin No.: 06-08-64-001B Date: October 20, 2009 Subject: Information on Side Door Window Glass Chipping Caused by Hanging Vehicle Key Lock Box Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add vehicles and model years and to include all types of door window glass. Please discard Corporate Bulletin Number 06-08-64-001A (Section 08 - Body & Accessories). - In several warranty parts review cases, side door window glass was observed with a chip or chips on the top side of the window glass. Dealer contacts confirmed that they use a vehicle key lock box on the front side door window glass. - A random selection of side door glass returns will be conducted to confirm adherence. If a side door glass is discovered with a chip or chips in the location previously described, the side door glass will be returned to the dealership for debit. Example of Side Door Glass - DO NOT place a vehicle key lock box on a side door window glass. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Front Door > Front Door Window Glass > System Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information > Page 7313 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Technical Service Bulletins > Customer Interest for Rear Door Handle: > 02-08-64-013 > May > 02 > Body/Frame - R/H Rear Cargo Door Handle Broken Rear Door Handle: Customer Interest Body/Frame - R/H Rear Cargo Door Handle Broken File In Section: 08 - Body and Accessories Bulletin No.: 02-08-64-013 Date: May, 2002 TECHNICAL Subject: Right Rear Cargo Door Handle Breaks (Replace Handle) Models: 1993-2002 Chevrolet and GMC M/L-Van Models (Astro, Safari) Condition Some customers may comment that the right rear door handle on the cargo door breaks. Correction A new handle has been released with additional material between the pivot stand-offs for improved durability. Replace the broken handle with the parts listed below. Refer to the Door sub-section of the Service Information (SI Document ID # 294840). Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Technical Service Bulletins > All Technical Service Bulletins for Rear Door Handle: > 02-08-64-013 > May > 02 > Body/Frame - R/H Rear Cargo Door Handle Broken Rear Door Handle: All Technical Service Bulletins Body/Frame - R/H Rear Cargo Door Handle Broken File In Section: 08 - Body and Accessories Bulletin No.: 02-08-64-013 Date: May, 2002 TECHNICAL Subject: Right Rear Cargo Door Handle Breaks (Replace Handle) Models: 1993-2002 Chevrolet and GMC M/L-Van Models (Astro, Safari) Condition Some customers may comment that the right rear door handle on the cargo door breaks. Correction A new handle has been released with additional material between the pivot stand-offs for improved durability. Replace the broken handle with the parts listed below. Refer to the Door sub-section of the Service Information (SI Document ID # 294840). Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Technical Service Bulletins > All Technical Service Bulletins for Rear Door Handle: > Page 7328 Rear Door Handle: By Symptom Technical Service Bulletin # 02-08-64-013 Date: 020501 Body/Frame - R/H Rear Cargo Door Handle Broken File In Section: 08 - Body and Accessories Bulletin No.: 02-08-64-013 Date: May, 2002 TECHNICAL Subject: Right Rear Cargo Door Handle Breaks (Replace Handle) Models: 1993-2002 Chevrolet and GMC M/L-Van Models (Astro, Safari) Condition Some customers may comment that the right rear door handle on the cargo door breaks. Correction A new handle has been released with additional material between the pivot stand-offs for improved durability. Replace the broken handle with the parts listed below. Refer to the Door sub-section of the Service Information (SI Document ID # 294840). Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Technical Service Bulletin # 02-08-64-013 Date: 020501 Body/Frame - R/H Rear Cargo Door Handle Broken File In Section: 08 - Body and Accessories Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Technical Service Bulletins > All Technical Service Bulletins for Rear Door Handle: > Page 7329 Bulletin No.: 02-08-64-013 Date: May, 2002 TECHNICAL Subject: Right Rear Cargo Door Handle Breaks (Replace Handle) Models: 1993-2002 Chevrolet and GMC M/L-Van Models (Astro, Safari) Condition Some customers may comment that the right rear door handle on the cargo door breaks. Correction A new handle has been released with additional material between the pivot stand-offs for improved durability. Replace the broken handle with the parts listed below. Refer to the Door sub-section of the Service Information (SI Document ID # 294840). Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Service and Repair > Outside Handle and Lock Cylinder Rear Door Handle: Service and Repair Outside Handle and Lock Cylinder Remove or Disconnect 1. Door trim panel. 2. Control rod from the outside handle. Pry the clip anchor out of the hole and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Outside handle nuts. 4. Outside handle. 5. License plate housing bolts. 6. License plate housing. 7. Door lock shield. 8. Control rod from the lock cylinder. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 9. Lock cylinder retainer. 10. Lock cylinder. Install or Connect 1. Clip to the lock cylinder. 2. Lock cylinder to the door. 3. Lock cylinder retainer. 4. Control rod to the lock cylinder through the clip. 5. Door lock shield. 6. License plate housing. 7. License plate housing bolts. 8. Clip to the outside handle. 9. Outside handle to the door. 10. Outside handle nuts. 11. Control rod to the outside handle through the clip. 12. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Service and Repair > Outside Handle and Lock Cylinder > Page 7332 Rear Door Handle: Service and Repair Side Doors Inside Handle Remove or Disconnect 1. Door trim panel. 2. Control rods from the handle. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Inside handle screws. 4. Inside handle from the door. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Handle > System Information > Service and Repair > Outside Handle and Lock Cylinder > Page 7333 1. Clips to the handle. 2. Inside handle to the door. 3. Inside handle screws. 4. Control rods to the handle and the clips. 5. Door trim panel. Outside Handle Remove or Disconnect 1. Door trim panel. 2. Control rods from the handle. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Outside handle nuts. 4. Outside handle from the door. Install or Connect 1. Clips to the handle. 2. Outside handle to the door. 3. Outside handle nuts. 4. Control rods to the handle and the clips 5. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Latch > System Information > Service and Repair > Remote Control Assembly Rear Door Latch: Service and Repair Remote Control Assembly Remove or Disconnect 1. Door trim panel. 2. Control rods from the remote control. Pry the clip anchor out of the hole, and push the clip away from the lever. 3. Remote control nuts. 4. Remote control. Install or Connect 1. Clips to the remote control. 2. Remote control. 3. Remote control nuts. 4. Control rods to the remote control through the clips. 5. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Rear Door > Rear Door Latch > System Information > Service and Repair > Remote Control Assembly > Page 7338 Rear Door Latch: Service and Repair Lock Assembly Remove or Disconnect 1. Door trim panel. 2. Upper control to lock rods. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and clip away from the lever. 3. Lower remote control to lock rods from the remote control. Use the procedure under step 2. 4. Lock screws. 5. Lock from the door. Install or Connect 1. Clips to the lock and remote control lever. 2. Lock to the door. 3. Lock screws. 4. Control rods. 5. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Sliding Door > Component Information > Technical Service Bulletins > Customer Interest for Sliding Door: > 661510 > Oct > 96 > Sliding Door - Rattles When Driving Over Bumps Sliding Door: Customer Interest Sliding Door - Rattles When Driving Over Bumps File In Section: 10 - Body Bulletin No.: 66-15-10 Date: October, 1996 Subject: Sliding Door Rattles When Driving Over Bumps (Replace Upper Door Locator) Models: 1985-96 Chevrolet and GMC M/L Models Condition An owner may comment about a rattle or chucking noise at the sliding door while driving over rough roads or bumps. Cause The sliding door upper locator ends are hitting against the locator socket on the "B" pillar. Correction Remove the upper locator and replace it with new locator, P/N 15742562. The new locator is slightly shorter to prevent the locator ends from making unwanted contact within the locator socket. Service Procedure Refer to Section 10A1, Door Adjustment, of the appropriate year M/L Service Manual. Parts Information P/N Description Qty 15742562 Locator 1 Parts are currently available from GMSPO. Warranty Information: For vehicles repaired under warranty, use: Labor Operation Labor Time B5000 Use Published Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Sliding Door > Component Information > Technical Service Bulletins > Customer Interest for Sliding Door: > 761502 > Oct > 95 > Sliding Door Window Latch May Self-Release Sliding Door: Customer Interest Sliding Door - Window Latch May Self-Release File In Section: 10 - Body Bulletin No.: 76-15-02 Date: October, 1995 Subject: Sliding Door Window May Self-Release (Install Washer) Models: 1985-94 Chevrolet and GMC Truck M/L Models This bulletin has been revised to add 1990-94 model years. Previous divisional publication numbers were: Chevrolet 89-73-10 GMC Truck 89-T-06 GM Canada 89-2-117 Condition Some owners may comment that the latch on the sliding door window may self-release when the vehicle is driven over rough roads or when the sliding door is being closed. Cause This condition is due to an incorrect window latch mounting pad surface tolerance. Correction Remove the four latch mounting screws and install a 1-1/2 to 2 mm (maximum thickness, 12.5 mm OD. diameter) washer, Part Number 2436161, or equivalent, between the door and each upper latch screw hole as shown in Figure No. 1. Reinstall the four mounting screws. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Sliding Door > Component Information > Technical Service Bulletins > Customer Interest for Sliding Door: > 761502 > Oct > 95 > Sliding Door Window Latch May Self-Release > Page 7351 Parts information P/N Description Qty 2436161 Flat Washer 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time C0482 Install Washer Frt 0.3 hr C0483 Install Washer Rear 0.3 hr Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Sliding Door > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sliding Door: > 661510 > Oct > 96 > Sliding Door - Rattles When Driving Over Bumps Sliding Door: All Technical Service Bulletins Sliding Door - Rattles When Driving Over Bumps File In Section: 10 - Body Bulletin No.: 66-15-10 Date: October, 1996 Subject: Sliding Door Rattles When Driving Over Bumps (Replace Upper Door Locator) Models: 1985-96 Chevrolet and GMC M/L Models Condition An owner may comment about a rattle or chucking noise at the sliding door while driving over rough roads or bumps. Cause The sliding door upper locator ends are hitting against the locator socket on the "B" pillar. Correction Remove the upper locator and replace it with new locator, P/N 15742562. The new locator is slightly shorter to prevent the locator ends from making unwanted contact within the locator socket. Service Procedure Refer to Section 10A1, Door Adjustment, of the appropriate year M/L Service Manual. Parts Information P/N Description Qty 15742562 Locator 1 Parts are currently available from GMSPO. Warranty Information: For vehicles repaired under warranty, use: Labor Operation Labor Time B5000 Use Published Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Sliding Door > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sliding Door: > 761502 > Oct > 95 > Sliding Door - Window Latch May Self-Release Sliding Door: All Technical Service Bulletins Sliding Door - Window Latch May Self-Release File In Section: 10 - Body Bulletin No.: 76-15-02 Date: October, 1995 Subject: Sliding Door Window May Self-Release (Install Washer) Models: 1985-94 Chevrolet and GMC Truck M/L Models This bulletin has been revised to add 1990-94 model years. Previous divisional publication numbers were: Chevrolet 89-73-10 GMC Truck 89-T-06 GM Canada 89-2-117 Condition Some owners may comment that the latch on the sliding door window may self-release when the vehicle is driven over rough roads or when the sliding door is being closed. Cause This condition is due to an incorrect window latch mounting pad surface tolerance. Correction Remove the four latch mounting screws and install a 1-1/2 to 2 mm (maximum thickness, 12.5 mm OD. diameter) washer, Part Number 2436161, or equivalent, between the door and each upper latch screw hole as shown in Figure No. 1. Reinstall the four mounting screws. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Doors > Sliding Door > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sliding Door: > 761502 > Oct > 95 > Sliding Door - Window Latch May Self-Release > Page 7361 Parts information P/N Description Qty 2436161 Flat Washer 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time C0482 Install Washer Frt 0.3 hr C0483 Install Washer Rear 0.3 hr Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Power Trunk / Liftgate Lock Actuator > Component Information > Technical Service Bulletins > Customer Interest for Power Trunk / Liftgate Lock Actuator: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Power Trunk / Liftgate Lock Actuator: Customer Interest Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Power Trunk / Liftgate Lock Actuator > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Power Trunk / Liftgate Lock Actuator: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Power Trunk / Liftgate Lock Actuator: All Technical Service Bulletins Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Handle > Component Information > Service and Repair Trunk / Liftgate Handle: Service and Repair Remove or Disconnect 1. Door trim panel. 2. Control rod from the outside handle. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Outside handle nuts. 4. Outside handle. 5. License plate housing bolts. 6. License plate housing. 7. Door lock shield. 8. Control rod from the lock cylinder. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 9. Lock cylinder retainer. 10. Lock cylinder. Install or Connect 1. Clip to the lock cylinder. 2. Lock cylinder to the door. 3. Lock cylinder retainer. 4. Control rod to the lock cylinder through the clip. 5. Door lock shield. 6. License plate housing. 7. License plate housing bolts. 8. Clip to the outside handle. 9. Outside handle to the door. 10. Outside handle nuts. 11. Control rod to the outside handle through the clip. 12. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Solenoid > Component Information > Locations Liftgate Wiring Harness To Liftgate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Solenoid > Component Information > Locations > Page 7382 C910, Liftgate Release Solenoid Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Switch > Component Information > Locations > Compartment Lid Release Switch, Rear Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Switch > Component Information > Locations > Compartment Lid Release Switch, Rear > Page 7387 Trunk / Liftgate Switch: Locations Liftgate Strut Switch Upper RH rear D-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear C203, Liftgate Release Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear > Page 7390 C918, Liftgate Key Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Doors, Hood and Trunk > Trunk / Liftgate > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear > Page 7391 Trunk / Liftgate Switch: Diagrams Liftgate Strut Switch C417, Liftgate Strut Switch C417, Liftgate Strut Switch (Body Side) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Exterior Moulding / Trim > Body Emblem > Component Information > Technical Service Bulletins > 06-08-111-004B - BULLETIN CANCELLATION NOTIFICATION Body Emblem: Technical Service Bulletins 06-08-111-004B - BULLETIN CANCELLATION NOTIFICATION TECHNICAL Bulletin No.: 06-08-111-004B Date: September 25, 2009 Subject: Information on Discoloration, Blistering, Peeling or Erosion of Various Exterior Emblems Including Chevy Bowtie (Bulletin Cancelled) Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2003-2009 HUMMER H2 2006-2009 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being cancelled. Please discard Corporate Bulletin Number 06-08-111-004A (Section 08 - Body & Accessories). This bulletin is being cancelled. The information is no longer applicable. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Frame > Component Information > Technical Service Bulletins > Body Squeeze Type Resistance Spot Welding/Equipment Frame: Technical Service Bulletins Body - Squeeze Type Resistance Spot Welding/Equipment INFORMATION Bulletin No.: 03-08-98-002B Date: June 30, 2010 Subject: Squeeze Type Resistance Spot Welding/Equipment Models: 2011 and Prior Passenger Cars and Trucks (Including Saturn) 2003-2010 HUMMER H2, H3 Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 03-08-98-002A (Section 08 - Body and Accessories). This bulletin provides guidelines for repair shops that wish to use squeeze type resistance spot welding (or simply, spot welding) as an alternative to MIG plug welding when performing collision repair procedures. The process of spot welding for attaching body panels and components has been around for many years and is similar to the production welding process used in assembly plants. Spot welding may be applicable in similar situations that are currently MIG plug welded. The following are some of the benefits of spot welding: - Less heat or burn damage - Less damage to corrosion protection - Drilling of holes not required - Replication of the production weld appearance Applicable components for this technology may be panels or components with flanges that are accessible with arms and tips supplied by the equipment manufacturer. Welds from this equipment should be applied on a one-for-one basis, next to the production welds. Here are some of the important factors in proper welding with this equipment. Important Proper use and safety training for each user of the equipment is a must. - Use equipment from companies that are able to produce welds that meet industry standards for size and strength. Equipment most likely to meet those standards at this time would be "inverter" technology and include the following suppliers (other suppliers may have comparable equipment): - Pro Spot (PR2000) - Elektron (M100) - Blackhawk (WEL700) - Car-O-Liner (CR500) For specific information about this and other equipment, call GM Dealer Equipment. - Ensure that the building power source is capable of meeting the equipment manufacturer's power requirement specifications. For example, fuse 60 amp, 208-230 V single or 3-phase, using supply wire of sufficient gauge to carry the current load. Consult with a qualified electrician for wiring assistance. - Prepare and perform sample welds for destructive testing made from similar materials. Perform this operation for each vehicle repaired and prior to actual repair. - Proper equipment maintenance - Proper weld tip alignment and maintenance - Ensure that metal flanges are clean and conform to each other A more complete description of these practices and standards can be found in the following publications: - SAE J-2667, Surface Vehicles Recommended Practice, http://www.sae.org - AWS D8.7-88, Recommended Practices Automotive Weld Quality - Resistance Spot Welding, http://www.aws.org/w/a/ - AWS D8.9-97, Recommended Practices for Test Methods for Evaluating the Resistance Spot Welding Behavior of Automotive Sheet Steels, http://www.aws.com Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Frame > Component Information > Technical Service Bulletins > Body Squeeze Type Resistance Spot Welding/Equipment > Page 7401 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Ash Tray > Component Information > Locations Cigarette Lighter And Courtesy Lamp (W/Auxiliary Lighting Package) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Carpet > Component Information > Technical Service Bulletins > Interior - Proper Use of Floor Mats Carpet: Technical Service Bulletins Interior - Proper Use of Floor Mats INFORMATION Bulletin No.: 10-08-110-001 Date: March 30, 2010 Subject: Information on Proper Use of Floor Mats Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2003-2009 HUMMER H2 2006-2010 HUMMER H3, H3T 2005-2009 Saab 9-7X GM's carpeted and all-weather (rubber) floor mats are especially designed for use in specific GM vehicles. Using floor mats that were not designed for the specific vehicle or using them incorrectly may cause interference with the accelerator or brake pedal. Please review the following safety guidelines regarding proper driver's side floor mat usage with the customer. Warning If a floor mat is the wrong size or is not properly installed, it can interfere with the accelerator pedal and/or brake pedal. Interference with the pedals can cause unintended acceleration and/or increased stopping distance which can cause a crash and injury. Make sure the floor mat does not interfere with the accelerator or brake pedal. - Do not flip the driver's floor mat over (in an effort to keep the floor mat clean) - Do not place anything on top of the driver's floor mat (e.g. carpet remnant, towel) - Do not place another mat on top of the driver's floor mat (e.g. do not place all-weather rubber mats over carpeted floor mats) - Only use floor mats that are designed specifically for your vehicle - When using replacement mats, make certain the mats do not interfere with the accelerator or brake pedal before driving the vehicle If your vehicle is equipped with a floor mat retaining pin(s) or clip(s), make certain the mat is installed correctly and according to the instructions. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Carpet > Component Information > Technical Service Bulletins > Interior - Proper Use of Floor Mats > Page 7410 After installing floor mats, make certain they cannot move and do not interfere with the accelerator or brake pedals. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Carpet > Component Information > Technical Service Bulletins > Interior - Proper Use of Floor Mats > Page 7411 Carpet: Technical Service Bulletins Interior - Elimination Of Unwanted Odors INFORMATION Bulletin No.: 00-00-89-027E Date: September 29, 2008 Subject: Eliminating Unwanted Odors in Vehicles Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and refine the instructions. Please discard Corporate Bulletin Number 00-00-89-027D (Section 00 - General Information). Vehicle Odor Elimination General Motors offers a product that may control or eliminate odors in the interior and luggage compartment areas of GM vehicles. GM Vehicle Care Odor Eliminator is a non-toxic, biodegradable odor remover. This odorless product has been shown to greatly reduce or remove objectionable smells of mold and mildew resulting from vehicle water leaks (as well as customer created odors, i.e. smoke). You may use GM Vehicle Care Odor Eliminator on fabrics, vinyl, leather, carpet and sound deadening materials. It may also be induced into HVAC modules and instrument panel ducts (for the control of non-bacterial related odors). Important: This product leaves no residual scent and should not be sold as or considered an air freshener. Product action may result in the permanent elimination of an odor and may be preferable to customers with allergies who are sensitive to perfumes. How to Use This Product GM Vehicle Care Odor Eliminator may be sprayed on in a ready-to-use formula or used in steam cleaners as an additive with carpet shampoo. This water-based, odorless product is safe for all vehicle interiors. Do not wet or soak any interior surface that plain water would cause to deteriorate, as this product will have the same effect. Also avoid letting this product come into contact with vinegar or any acidic substance. Acid-based products will hamper the effectiveness of, or render GM Vehicle Care Odor Eliminator inert. Note: Complete eight page treatment sheets are enclosed within each case of GM Vehicle Care Odor Eliminator. These treatment instructions range from simple vehicle odor elimination to full step by step procedures for odor removal from water leaks. If lost, contact 800-977-4145 to get a replacement set faxed or e-mailed to your dealership. Instructions and cautions are printed on the bottle, but additional help is available. If you encounter a difficult to eliminate or reoccurring odor, you may call 1-800-955-8591 (in Canada, 1-800-977-4145) to obtain additional information and usage suggestions. Important: This product may effectively remove odors when directly contacting the odor source. It should be used in conjunction with diagnostic procedures (in cases such as a water leak) to first eliminate the root cause of the odor, and then the residual odor to permanently correct the vehicle condition. Vehicle Waterleak Odor Elimination STEP ONE: Confirm that all water leaks have been repaired. Determine what areas of the vehicle were water soaked or wet. Components with visible mold/mildew staining should be replaced. Isolate the odor source inside the vehicle. Often an odor can be isolated to an area or component of the vehicle interior by careful evaluation. Odor evaluation may need to be performed by multiple persons. Another method of isolating an odor source is to remove and segregate interior trim and components. Plastic sheeting or drop cloths can be used to confine seats, headliners, etc. to assist in evaluation and diagnoses. If appropriate the vehicle and interior trim should be evaluated separately to determine if the odor stays with the vehicle or the interior components. Odors that stay with the vehicle may be isolated to insulating and sound deadening materials (i.e. water leak at the windshield or standing water in the front foot well area caused mold/mildew to form on the bulkhead or kick panel sound deadening pads. If the interior is removed the floor pan and primed/painted surfaces should be treated with bleach/soap solution, rinsed with clean water and dried. Interior surfaces should then be treated with GM Vehicle Care Odor Eliminator product before reinstalling carpet or reassembling. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Carpet > Component Information > Technical Service Bulletins > Interior - Proper Use of Floor Mats > Page 7412 The GM Vehicle Care Odor Eliminator product is an effective odor elimination product when used properly. It must come into direct contact with the odor source. It should be used in conjunction with diagnostic procedures to first eliminate the root cause of the odor. Some procedures for use after odor root cause correction are: STEP TWO: ^ Use the trigger spray head. ^ Put a drop of dish soap the size of a quarter in the bottom of a bottle. ^ Add 8 oz. of GM Vehicle Care Odor Eliminator (1 cup) to the dish soap and top off the bottle with tap water. ^ This formula should be used on hard surfaces (dash, interior plastic molding, and floor pan) STEP THREE: The third step to neutralizing the vehicle is a light to medium treatment of all carpeting and upholstered seats with the GM Vehicle Care Odor Eliminator formula and a wide fan spray setting (at full strength) (i.e.: carpeting on the driver's side requires 4-5 triggers pulls for coverage). The headliner and trunk should be sprayed next. Lightly brushing the formula into the carpeting and upholstery is a recommended step for deep odor problems. The dash and all hard surfaces should be sprayed with dish soap/water mixture. Let stand for 1-2 minutes then wipe off the surface. STEP FOUR: (vehicle ventilation system treatment) The ventilation system is generally the last step in the treatment of the vehicle. a. Spray the GM Vehicle Care Odor Eliminator formula into all dash vents. (1-2 trigger pulls per vent). b. Start the vehicle and turn the vehicle fan on high cool (not A/C setting). c. Spray the formula (10 trigger pulls) into the outside fresh air intake vent (cowl at base of windshield) d. Enter the vehicle after 1 minute and wipe off the excess formula spurting out of the dash vents. e. Smell the air coming from the dash vents. If odors are still present, spray another 5 triggers into the cowl, wait another minute and smell the results. Once you have obtained a fresh, clean smell coming from the vents, turn the system to the A/C re-circulation setting. Roll up the windows, spray 3-5 pumps into the right lower IP area and let the vehicle run with the fan set on high for 5-7 minutes. Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. Additional Suggestions to Increase Customer Satisfaction Here are some additional ideas to benefit your dealership and to generate greater customer enthusiasm for this product. ^ Keep this product on-hand for both the Service Department and the Used Car lot. Add value to your used car trades; treat loaner and demo cars during service and at final sale to eliminate smoke, pet, and other common odors offensive to customers. Make deodorizing a vehicle part of your normal vehicle detailing service. ^ Consider including GM Vehicle Care Odor Eliminator as a give-away item with new vehicle purchases. Many dealers give away as "gifts" various cleaning supplies at time of delivery. GM Odor Eliminator is one of a few products GM offers that has as many uses in the home as in the vehicle. Customers may find this product can be used for a host of recreational activities associated with their new vehicle, such as deodorizing a boat they tow, or a camper. ^ GM Odor Eliminator and many of the GM Vehicle Care products offer you the chance to increase dealership traffic as these superior quality products cannot be purchased in stores. Many Dealerships have product displays at the parts counter. Consider additional displays in the Customer Service Lounge, the Showroom and at the Service Desk or Cashier Window. Many customers who purchase vehicles and receive regular maintenance at your dealership may never visit the parts counter, and subsequently are not exposed to the variety and value that these products offer. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Carpet > Component Information > Technical Service Bulletins > Interior - Proper Use of Floor Mats > Page 7413 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Dash Board / Instrument Panel <--> [Dashboard / Instrument Panel] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Dash Board / Instrument Panel <--> [Dashboard / Instrument Panel] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 7419 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Restraint Systems/Air Bag Systems/Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Interior Moulding / Trim > Dash Board / Instrument Panel <--> [Dashboard / Instrument Panel] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 7420 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors Door Locks: Service and Repair Front Doors Binding Lock Cylinders Apply the proper lubrication, and binding or sticking door lock cylinders and keys that are hard to insert or remove, in many cases, will be corrected. The recommended material for lubricating these components is Multi-Purpose Lubricant Superlube® GM P/N 12346241 or equivalent. Penetrating lubricants such as GM P/N 1052949 and WD-40® are not recommended These lubricants wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. Refer to steps 2 through 5 below for proper methods of lubrication in order to use GM P/N 1052949 or WD-40® in order to unfreeze or loosen lock cylinder components. Perform the following procedure in order to repair frozen lock cylinders due to cold weather: 1. Apply heat to the cylinder with a heat gun while being careful not to damage any painted surfaces. 2. Hold the door lock cylinder shutter open with a paper clip (or similar item). 3. Use compressed air and a blow gun attachment in order to force air into the cylinders. 4. Inject a small amount of lubricant into the cylinder while holding the shutter door open. Refer to the above recommendations. 5. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Lock Lever Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7426 1. Door trim panel. 2. Power door lock motor to remove lever rod. 3. Remote lever to lock assembly rod. 4. Remote lever to inside lock lever rod. 5. Remote lever to door rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 6. Remote lever from the door. Install or Connect 1. Remote lever to the door. 2. Remote lever to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the handle to the door. 3. Remote lever to inside door lock lever rod. 4. Remote lever to lock assembly rod. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7427 5. Power door lock motor to remote lever rod. 6. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7428 Door Locks: Service and Repair Side Doors Binding Lock Cylinders Apply the proper lubrication, and binding or sticking door lock cylinders and keys that are hard to insert or remove, in many cases, will be corrected. The recommended material for lubricating these components is Multi-Purpose Lubricant Superlube® GM P/N 12346241 or equivalent. Penetrating lubricants such as GM P/N 1052949 and WD-40® are not recommended These lubricants wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. Refer to steps 2 through 5 below for proper methods of lubrication in order to use GM P/N 1052949 or WD-40® in order to unfreeze or loosen lock cylinder components. Perform the following procedure in order to repair frozen lock cylinders due to cold weather: 1. Apply heat to the cylinder with a heat gun while being careful not to damage any painted surfaces. 2. Hold the door lock cylinder shutter open with a paper clip (or similar item). 3. Use compressed air and a blow gun attachment in order to force air into the cylinders. 4. Inject a small amount of lubricant into the cylinder while holding the shutter door open. Refer to the above recommendations. 5. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Outside Lock Cylinder Remove or Disconnect 1. Door trim panel. 2. Lock cylinder rod. Pry the clip anchor out of the hole and push the clip away from the lever. Pull the rod and clip away from the lever. 3. Lock cylinder retainer. If the retainer breaks, replace it. 4. Lock cylinder and gasket. Install or Connect 1. Lock cylinder clip to the cylinder. 2. Lock cylinder and gasket to the door. 3. Lock cylinder retainer. 4. Lock cylinder rod to the cylinder through the clip. 5. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7429 Door Locks: Service and Repair Rear Doors Lock Assembly Remove or Disconnect 1. Door trim panel. 2. Control rods from the lock assembly. Pry the clip anchor out of the hole and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Door to lock screws. 4. Lock from the vehicle. Install or Connect 1. Clips to the lock. 2. Lock to the vehicle. 3. Door to lock screws. 4. Control rods to the lock assembly through the clips. 5. Door trim panel. Binding Lock Cylinders Apply the proper lubrication, and binding or sticking door lock cylinders and keys that are hard to insert or remove, in many cases, will be corrected. The recommended material for lubricating these components is Multi-Purpose Lubricant Superlube® GM P/N 12346241 or equivalent. Penetrating lubricants such as GM P/N 1052949 and WD-40® are not recommended These lubricants wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. Refer to steps 2 through 5 below for proper methods of lubrication in order to use GM P/N 1052949 or WD-40® in order to unfreeze or loosen lock cylinder components. Perform the following procedure in order to repair frozen lock cylinders due to cold weather: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7430 1. Apply heat to the cylinder with a heat gun while being careful not to damage any painted surfaces. 2. Hold the door lock cylinder shutter open with a paper clip (or similar item). 3. Use compressed air and a blow gun attachment in order to force air into the cylinders. 4. Inject a small amount of lubricant into the cylinder while holding the shutter door open. Refer to the above recommendations. 5. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Outside Handle and Lock Cylinder Remove or Disconnect 1. Door trim panel. 2. Control rod from the outside handle. Pry the clip anchor out of the hole and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Outside handle nuts. 4. Outside handle. 5. License plate housing bolts. 6. License plate housing. 7. Door lock shield. 8. Control rod from the lock cylinder. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 9. Lock cylinder retainer. 10. Lock cylinder. Install or Connect 1. Clip to the lock cylinder. 2. Lock cylinder to the door. 3. Lock cylinder retainer. 4. Control rod to the lock cylinder through the clip. 5. Door lock shield. 6. License plate housing. 7. License plate housing bolts. 8. Clip to the outside handle. 9. Outside handle to the door. 10. Outside handle nuts. 11. Control rod to the outside handle through the clip. 12. Door trim panel. Remote Lock Lever Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7431 Remove or Disconnect 1. Door trim panel. 2. Control rods from the lever. 3. Lever to door rivet. Grind the head from the rivet. 4. Lever from the door. Install or Connect 1. Lever to the door. 2. Lever to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer; and nut, to re-attach the lever to the door. 3. Control rods to the lever 4. Door trim panel Door Lock Actuator Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7432 1. Negative (-) battery cable. 2. Door trim panel. 3. Actuator to lever rod. 4. Actuator to door rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 5. Actuator from the door Install or Connect 1. Actuator to the door. 2. Actuator to door fasteners. Use a 6mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the actuator to the door. 3. Actuator to lever rod. 4. Door trim panel. 5. Negative (-) battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7433 Door Locks: Service and Repair Liftgate Binding Lock Cylinders Apply the proper lubrication, and binding or sticking door lock cylinders and keys that are hard to insert or remove, in many cases, will be corrected. The recommended material for lubricating these components is Multi-Purpose Lubricant Superlube® GM P/N 12346241 or equivalent. Penetrating lubricants such as GM P/N 1052949 and WD-40® are not recommended These lubricants wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. Refer to steps 2 through 5 below for proper methods of lubrication in order to use GM P/N 1052949 or WD-40® in order to unfreeze or loosen lock cylinder components. Perform the following procedure in order to repair frozen lock cylinders due to cold weather: 1. Apply heat to the cylinder with a heat gun while being careful not to damage any painted surfaces. 2. Hold the door lock cylinder shutter open with a paper clip (or similar item). 3. Use compressed air and a blow gun attachment in order to force air into the cylinders. 4. Inject a small amount of lubricant into the cylinder while holding the shutter door open. Refer to the above recommendations. 5. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Outside Handle and Lock Cylinder Remove or Disconnect 1. Door trim panel. 2. Control rod from the outside handle. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Outside handle nuts. 4. Outside handle. 5. License plate housing bolts. 6. License plate housing. 7. Door lock shield. 8. Control rod from the lock cylinder. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 9. Lock cylinder retainer. 10. Lock cylinder. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7434 1. Clip to the lock cylinder. 2. Lock cylinder to the door. 3. Lock cylinder retainer. 4. Control rod to the lock cylinder through the clip. 5. Door lock shield. 6. License plate housing. 7. License plate housing bolts. 8. Clip to the outside handle. 9. Outside handle to the door. 10. Outside handle nuts. 11. Control rod to the outside handle through the clip. 12. Door trim panel. Liftgate Lock Actuator Remove or Disconnect 1. Negative (-) battery cable. 2. Liftgate interior molding. 3. Control rods right side and left side from the actuator lever rod. 4. Actuator to liftgate rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 5. Actuator from the liftgate. Install or Connect 1. Actuator to the littgate. 2. Actuator to littgate fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washei; and nut, to re-attach the actuator to the door. 3. Actuator lever rod to control rods right side and left side. 4. Liftgate interior molding. 5. Negative (-) battery cable. Remote Lock Lever Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7435 1. Door trim panel. 2. Control rods from the lever. 3. Lever to door rivet. Grind the head from the rivet. 4. Lever from the door. Install or Connect 1. Lever to the door. 2. Lever to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the lever to the door. 3. Control rods to lever. 4. Door trim panel. Lower Door Lock Actuator Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7436 1. Negative (-) battery cable. 2. Door trim panel. 3. Actuator to lever rod. 4. Actuator to door rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 5. Actuator from the door. Install or Connect 1. Actuator to the door. 2. Actuator to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the actuator to the door. 3. Actuator to lever rod. 4. Door trim panel. 5. Negative (-) battery cable. Lock Assembly Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Door Locks > Component Information > Service and Repair > Front Doors > Page 7437 1. Door trim panel. 2. Control rods from the lock assembly. Pry the clip anchor out of the hole, and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Door to lock screws. 4. Lock from the vehicle. Install or Connect 1. Clips to the lock. 2. Lock to the vehicle. 3. Door to lock screws. 4. Control rods to the lock assembly through the clips. 5. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information Key: Technical Service Bulletins Locks - Key Code Security Rules and Information INFORMATION Bulletin No.: 10-00-89-010 Date: May 27, 2010 Subject: Key Code Security Rules and Information on GM KeyCode Look-Up Application (Canada Only) Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saturn and Saab 2002 and Prior Isuzu Attention: This bulletin has been created to address potential issues and questions regarding KeyCode security. This bulletin should be read by all parties involved in KeyCode activity, including dealer operator, partner security coordinator, sales, service and parts departments. A copy of this bulletin should be printed and maintained in the parts department for use as a reference. Important U.S. dealers should refer to Corporate Bulletin Number 10-00-89-009. Where Are Key Codes Located? General Motors provides access to KeyCodes through three sources when a vehicle is delivered to a dealer. Vehicle KeyCodes are located on the original vehicle invoice to the dealership. There is a small white bar coded tag sent with most new vehicles that also has the key code printed on it. Dealerships should make a practice of comparing the tag's keycode numbers to the keycode listed on the invoice. Any discrepancy should be reported immediately to the GM of Canada Key Code Inquiry Desk. Remember to remove the key tag prior to showing vehicles to potential customers. The third source for Key codes is through the GM KeyCode Look-Up feature within the OEConnection D2DLink application. KeyCode Look-Up currently goes back 17 previous model years from the current model year. When a vehicle is received by the dealership, care should be taken to safeguard the original vehicle invoice and KeyCode tag provided with the vehicle. Potential customers should not have access to the invoice or this KeyCode tag prior to the sale being completed. After a sale has been completed, the KeyCode information belongs to the customer and General Motors. Tip Only the original invoice contains key code information, a re-printed invoice does not. GM KeyCode Look-Up Application for GM of Canada Dealers All dealers should review the General Motors of Canada KeyCode Look-Up Policies and Procedures (Service Policy & Procedures Manual Section 3.1.6 "Replacement of VIN plates & keys"). Please note that the KeyCode Access site is restricted. Only authorized users should be using this application. Please see your Parts Manager for site authorized users. KeyCode Look-Up currently goes back 17 years from current model year. Important notes about security: - Users may not access the system from multiple computers simultaneously. - Users may only request one KeyCode at a time. - KeyCode information will only be available on the screen for 2 minutes. - Each user is personally responsible for maintaining and protecting their password. - Never share your password with others. - User Id's are suspended after 6 consecutive failed attempts. - User Id's are disabled if not used for 90 days. - Processes must be in place for regular dealership reviews. - The Parts Manager (or assigned management) must have processes in place for employee termination or life change events. Upon termination individuals access must be turned off immediately and access should be re-evaluated upon any position changes within the dealership. - If you think your password or ID security has been breached, contact Dealer Systems Support at 1-800-265-0573. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information > Page 7442 Each user will be required to accept the following agreement each time the KeyCode application is used. Key Code User Agreement - Key codes are proprietary information belonging to General Motors Corporation and to the vehicle owner. - Unauthorized access to, or use of, key code information is unlawful and may subject the user to criminal and civil penalties. - This information should be treated as strictly confidential and should not be disclosed to anyone unless authorized. I will ensure that the following information is obtained prior to releasing any Key Code information: 1. Government issued picture ID (Drivers License) 2. Registration or other proof of ownership. Registration should have normal markings from the Province that issued the registration and possibly the receipt for payment recorded as well. Important - GM takes this agreement seriously. Each user must be certain of vehicle ownership before giving out key codes. - When the ownership of the vehicle is in doubt, dealership personnel should not provide the information. Key code requests should never be received via a fax or the internet and key codes should never be provided to anyone in this manner. A face to face contact with the owner of the vehicle is the expected manner that dealers will use to release a key code or as otherwise stipulated in this bulletin or other materials. - Key codes should NEVER be sent via a fax or the internet. - Each Dealership should create a permanent file to document all KeyCode Look Up transactions. Requests should be filed by VIN and in each folder retain copies of the following: - Government issued picture ID (Drivers License) - Registration or other proof of ownership. - Copy of the paid customer receipt which has the name of the employee who cut and sold the key to the customer. - Do not put yourself or your Dealership in the position of needing to "explain" a KeyCode Look Up to either GM or law enforcement officials. - Dealership Management has the ability to review all KeyCode Look-Up transactions. - Dealership KeyCode documentation must be retained for two years. Frequently Asked Questions (FAQs) for GM of Canada Dealers How do I request a KeyCode for customer owned vehicle that is not registered? Scrapped, salvaged or stored vehicles that do not have a current registration should still have the ownership verified by requesting the vehicle title, current insurance policy and / or current lien holder information from the customers financing source. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. In these cases, a short description of the vehicle (scrapped, salvaged, etc.) and the dealership location should be kept on file. Any clarifying explanation should be entered into the comments field. How do I document a KeyCode request for a vehicle that is being repossessed? The repossessor must document ownership of the vehicle by providing a court ordered repossession order and lien-holder documents prior to providing key code information. Copies of the repossessors Drivers License and a business card should be retained by the dealership for documentation. What do I do if the registration information is locked in the vehicle? Every effort should be made to obtain complete information for each request. Each Dealership will have to decide on a case by case basis if enough information is available to verify the customer's ownership of the vehicle. Other forms of documentation include vehicle title, insurance policy, and or current lien information from the customers financing source. Dealership Management must be involved in any request without complete information. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. Can I get a print out of the information on the screen? It is important to note that the Key Code Look Up Search Results contain sensitive and/or proprietary information. For this reason GM recommends against printing it. If the Search Results must be printed, store and/or dispose of the printed copy properly to minimize the risk of improper or illegal use. Who in the dealership has access to the KeyCode application? Dealership Parts Manager (or assigned management) will determine, and control, who is authorized to access the KeyCode Look Up application. However, we anticipate that dealership parts and service management will be the primary users of the application. The KeyCode Look Up application automatically tracks each user activity session. Information tracked by the system includes: User name, User ID, all other entered data and the date/time of access. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information > Page 7443 What if I input the VIN incorrectly? If an incorrect VIN is entered into the system (meaning that the system does not recognize the VIN or that the VIN has been entered incorrectly) the system will return an error message. If I am an authorized user for the KeyCode application, can I access the application from home? Yes. What if I suspect key code misuse? Your dealership should communicate the proper procedures for requesting key codes. Any suspicious activity either within the dealership or externally should be reported to Dealer Systems Support at 1-800-265-0573 or GM of Canada Key Code Inquiry Desk at 1-905-644-4892. Whose key codes can I access through the system? At this time the following Canadian vehicle codes are available through the system: Chevrolet, Cadillac, Buick, Pontiac, GMC, HUMMER (H2 and H3 only), Oldsmobile, Saturn, Saab and Isuzu (up to 2002 model year) for a maximum of 17 model years. What should I do if I enter a valid VIN and the system does not produce any key code information? Occasionally, the KeyCode Look Up application may not produce a key code for a valid VIN. This may be the result of new vehicle information not yet available. In addition, older vehicle information may have been sent to an archive status. If you do not receive a key code returned for valid VIN, you should contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. How do I access KeyCodes if the KeyCode Look-up system is down? If the KeyCode Look-up system is temporarily unavailable, you can contact the original selling dealer who may have it on file or contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the customer is dealing with an emergency lock-out situation, you need to have the customer contact Roadside assistance, OnStar if subscribed, or 911. What should I do if the KeyCode from the look-up system does not work on the vehicle? On occasion a dealer may encounter a KeyCode that will not work on the vehicle in question. In cases where the KeyCode won't work you will need to verify with the manufacturer of the cutting equipment that the key has been cut correctly. If the key has been cut correctly you may be able to verify the proper KeyCode was given through the original selling dealer. When unable to verify the KeyCode through the original selling dealer contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the key has been cut correctly and the code given does not work, the lock cylinder may have been changed. In these situations following the proper SI document for recoding a key or replacing the lock cylinder may be necessary. How long do I have to keep KeyCode Records? Dealership KeyCode documentation must be retained for two years. Can I get a KeyCode changed in the Look-Up system? Yes, KeyCodes can be changed in the Look-Up system if a lock cylinder has been changed. Contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. What information do I need before I can provide a driver of a company fleet vehicle Keys or KeyCode information? The dealership should have a copy of the individual's driver's license, proof of employment and registration. If there is any question as to the customer's employment by the fleet company, the dealer should attempt to contact the fleet company for verification. If there is not enough information to determine ownership and employment, this information should not be provided. How do I document a request from an Independent Repair facility for a KeyCode or Key? The independent must provide a copy of their driver's license, proof of employment and signed copy of the repair order for that repair facility. The repair order must include customer's name, address, VIN, city, province and license plate number. Copies of this information must be included in your dealer KeyCode file. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Key > Component Information > Technical Service Bulletins > Locks - Key Code Security Rules and Information > Page 7444 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > Customer Interest: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Keyless Entry Transmitter: Customer Interest Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester Keyless Entry Transmitter: All Technical Service Bulletins Tools - Keyless Entry Transmitter Tester File In Section: 9 - Accessories Bulletin No.: 83-90-12 Date: August, 1998 INFORMATION Subject: Essential Tool J 43241 Remote Keyless Entry and Passive Keyless Entry Transmitter Tester Models: 1990-99 Passenger Cars and Trucks with Remote Keyless Entry or Passive Keyless Entry Systems A new essential tool, J 43241 Remote Keyless Entry Transmitter Tester, has been sent to all GM Dealers. This tester can be used on all RKE and PKE systems, on past as well as current models. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester > Page 7459 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Keyless Entry Transmitter: > 66-90-03 > Jun > 97 > Keyless Entry - Unintended Release of Rear Hatch Keyless Entry Transmitter: All Technical Service Bulletins Keyless Entry - Unintended Release of Rear Hatch File In Section: 9 - Accessories Bulletin No.: 66-90-03 Date: June, 1997 Subject: Unintended Release of Rear Hatch (Replace Transmitter Cover) Models: 1994-96 Chevrolet and GMC C/K, S/T, M/L, G Models 1994 Oldsmobile Bravada 1996 Oldsmobile Bravada Condition An owner may report that the Rear Hatch Releases without their being aware of it. Cause The Keyless Entry Transmitter Button is unintentionally bumped activating the hatch release. Correction Replace the Keyless Entry Transmitter Cover. The revised cover has a deeper recess around the release button making it less prone to inadvertent bumping. Parts Information P/N Description Qty 15740707 Bezel, Transmitter Cover 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Op Description Labor Time R4490 Control Assembly 0.3 hr Cover - Replace Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Other Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester Keyless Entry Transmitter: All Technical Service Bulletins Tools - Keyless Entry Transmitter Tester File In Section: 9 - Accessories Bulletin No.: 83-90-12 Date: August, 1998 INFORMATION Subject: Essential Tool J 43241 Remote Keyless Entry and Passive Keyless Entry Transmitter Tester Models: 1990-99 Passenger Cars and Trucks with Remote Keyless Entry or Passive Keyless Entry Systems A new essential tool, J 43241 Remote Keyless Entry Transmitter Tester, has been sent to all GM Dealers. This tester can be used on all RKE and PKE systems, on past as well as current models. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Remote Keyless Entry <--> [Keyless Entry] > Keyless Entry Transmitter > Component Information > Technical Service Bulletins > All Other Service Bulletins for Keyless Entry Transmitter: > 83-90-12 > Aug > 98 > Tools - Keyless Entry Transmitter Tester > Page 7469 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Locations > Front Power Door Lock Actuator: Locations Front Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Locations > Front > Page 7475 RH Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Locations > Front > Page 7476 Side Door Lock Motor And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Locations > Front > Page 7477 Rear Door Lock And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Diagrams > Left Front Door Lock Actuator C505, Front LH Power Door Lock Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Diagrams > Left Front Door Lock Actuator > Page 7480 C900, Rear Door Lock Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Diagrams > Left Front Door Lock Actuator > Page 7481 C602, Front RH Power Door Lock Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Diagrams > Left Front Door Lock Actuator > Page 7482 C802, Swinging Or Sliding Side Door Lock Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors Power Door Lock Actuator: Service and Repair Front Doors Remove or Disconnect 1. Negative (-) battery cable. 2. Door trim panel. 3. Power door lock motor to remote lever rod. 4. Power door lock motor wiring harness. 5. Motor to door bolts. 6. Motor from the door. Install or Connect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7485 1. Motor to the door. 2. Motor to door bolts. 3. Power door lock motor wiring harness. 4. Power door lock motor to remote lever rod. 5. Door trim panel. 6. Negative (-) battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7486 Power Door Lock Actuator: Service and Repair Side Doors Remove or Disconnect 1. Negative (-) battery cable. 2. Door trim panel. 3. Wiring harness from the motor. 4. Motor to door rivets. Using a 5 mm (3/16 inch) drill bit, drill the head from the rivet. 5. Motor from the door. Install or Connect 1. Motor to the door. The lock lever must fit into the arm of the motor. 2. Fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer and nut to reattach the motor to the door. 3. Wiring harness to the motor. 4. Door trim panel. 5. Negative (-) battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7487 Power Door Lock Actuator: Service and Repair Rear Doors Remote Lock Lever Remove or Disconnect 1. Door trim panel. 2. Control rods from the lever. 3. Lever to door rivet. Grind the head from the rivet. 4. Lever from the door. Install or Connect 1. Lever to the door. 2. Lever to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer; and nut, to re-attach the lever to the door. 3. Control rods to the lever 4. Door trim panel Door Lock Actuator Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7488 1. Negative (-) battery cable. 2. Door trim panel. 3. Actuator to lever rod. 4. Actuator to door rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 5. Actuator from the door Install or Connect 1. Actuator to the door. 2. Actuator to door fasteners. Use a 6mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the actuator to the door. 3. Actuator to lever rod. 4. Door trim panel. 5. Negative (-) battery cable. Remote Control Assembly Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7489 1. Door trim panel. 2. Control rods from the remote control. Pry the clip anchor out of the hole, and push the clip away from the lever. 3. Remote control nuts. 4. Remote control. Install or Connect 1. Clips to the remote control. 2. Remote control. 3. Remote control nuts. 4. Control rods to the remote control through the clips. 5. Door trim panel. Lock Assembly Remove or Disconnect Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7490 1. Door trim panel. 2. Control rods from the lock assembly. Pry the clip anchor out of the hole and push the clip away from the lever. Pull the rod and the clip away from the lever. 3. Door to lock screws. 4. Lock from the vehicle. Install or Connect 1. Clips to the lock. 2. Lock to the vehicle. 3. Door to lock screws. 4. Control rods to the lock assembly through the clips. 5. Door trim panel. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7491 Power Door Lock Actuator: Service and Repair Liftgate Liftgate Lock Actuator Remove or Disconnect 1. Negative (-) battery cable. 2. Liftgate interior molding. 3. Control rods right side and left side from the actuator lever rod. 4. Actuator to liftgate rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 5. Actuator from the liftgate. Install or Connect 1. Actuator to the littgate. 2. Actuator to littgate fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washei; and nut, to re-attach the actuator to the door. 3. Actuator lever rod to control rods right side and left side. 4. Liftgate interior molding. 5. Negative (-) battery cable. Remote Lock Lever Remove or Disconnect 1. Door trim panel. 2. Control rods from the lever. 3. Lever to door rivet. Grind the head from the rivet. 4. Lever from the door. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Actuator > Component Information > Service and Repair > Front Doors > Page 7492 Install or Connect 1. Lever to the door. 2. Lever to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the lever to the door. 3. Control rods to lever. 4. Door trim panel. Lower Door Lock Actuator Remove or Disconnect 1. Negative (-) battery cable. 2. Door trim panel. 3. Actuator to lever rod. 4. Actuator to door rivets. Drill out the head of the rivet using a 5 mm (3/16 inch) drill bit. 5. Actuator from the door. Install or Connect 1. Actuator to the door. 2. Actuator to door fasteners. Use a 6 mm (1/4 inch) diameter bolt 13 mm (1/2 inch) long with a spring washer, and nut, to re-attach the actuator to the door. 3. Actuator to lever rod. 4. Door trim panel. 5. Negative (-) battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Control Module > Component Information > Locations > Door Lock Delay Module Power Door Lock Control Module: Locations Door Lock Delay Module Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Control Module > Component Information > Locations > Door Lock Delay Module > Page 7497 Liftgate Wiring - RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear > Page 7502 Power Door Lock Relay: Locations Door Lock Delay Relay Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear > Page 7503 Power Door Lock Relay: Locations Door Lock Relay Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Relay > Component Information > Diagrams > Door Lock Delay Relay C201A, Door Lock Delay Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Relay > Component Information > Diagrams > Door Lock Delay Relay > Page 7506 Power Door Lock Relay: Diagrams Door Lock Relay C241, Door Lock Relay C204A, Power Door Lock Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Switch > Component Information > Locations > Component Locations Power Door Lock Switch: Component Locations Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Switch > Component Information > Locations > Component Locations > Page 7511 RH Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Switch > Component Information > Locations > Component Locations > Page 7512 Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Locks > Power Locks > Power Door Lock Switch > Component Information > Locations > Page 7513 Power Door Lock Switch: Diagrams C604, Front RH Power Door Lock Switch C504, Front Door Lock Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Heated Element, Mirror > Component Information > Technical Service Bulletins > Mirrors - Heated Mirrors, Defrosting Time Heated Element: Technical Service Bulletins Mirrors - Heated Mirrors, Defrosting Time INFORMATION Bulletin No.: 08-08-64-011A Date: February 25, 2010 Subject: Information on Heated Electrochromatic Outside Rearview Mirror Performance Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 08-08-64-011 (Section 08 - Body and Accessories). Defrosting Time/Performance Concern The electrochromatic (auto-dimming) outside rearview mirror used on the driver's side of many GM vehicles is slower to defrost than the passenger side outside rearview mirror. This is a normal condition. The glass on the driver's side electrochromatic mirror is twice as thick as the traditional glass on the passenger side mirror. The heating elements for the mirrors on both sides draw the same wattage, therefore the driver's side mirror will take approximately twice as long to defrost as the passenger mirror (approximately four minutes versus two minutes). Should a customer indicate that the driver's side heated mirror is not functioning correctly, verify it's function based upon this information prior to replacing the mirror. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Motor > Component Information > Locations > LH Outside Mirror Power Mirror Motor: Locations LH Outside Mirror Inside LH mirror housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Motor > Component Information > Locations > LH Outside Mirror > Page 7523 Power Mirror Motor: Locations RH Outside Mirror Inside RH mirror housing Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Switch > Component Information > Locations > Component Locations Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Switch > Component Information > Locations > Component Locations > Page 7528 Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch C248, Crossbody To Mirror Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch > Page 7531 C275, Power Mirror Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Mirrors > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch > Page 7532 C248, Mirror Switch To Crossbody Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > Customer Interest: > 05-08-51-008C > Jun > 09 > Body - Bumps or Rust Colored Spots in Paint Paint: Customer Interest Body - Bumps or Rust Colored Spots in Paint TECHNICAL Bulletin No.: 05-08-51-008C Date: June 22, 2009 Subject: Bumps or Rust Colored Spots in Paint Due to Rail or Iron Dust (Remove Rail Dust) Models: 1994-2010 GM Passenger Cars and Trucks (Including Saturn) 2003-2010 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-08-51-008B (Section 08 - Body and Accessories). Condition Visible rust colored spots or bumps on a vehicle's paint surface from rail or iron dust. Cause Rail dust comes from tiny iron particles produced from the friction between train wheels and the tracks and gets deposited on the vehicle surfaces. Iron dust can get deposited on the surface if the vehicle is stored near any operation producing iron dust such as an iron ore yard. Either material can lay on top of, or become embedded in, the paint surface. Correction Because the severity of the condition varies, proper diagnosis of the damage is critical to the success of repairs. Diagnosis should be performed on horizontal surfaces (hood, roof, deck lid, pick up box, etc.) after the vehicle has been properly cleaned. There are two types of repair materials recommended to repair rail dust or iron dust: 1. GEL TYPE OXALIC ACID: - Has the characteristics of the liquid type oxalic acid but stays where you put it because of its gel consistency. 2. CLAY TYPE NON-ACID BASED: - Requires surface lubricant during use. - Has different grades available. Caution Rail dust remover (Oxalic Acid) is an acidic substance containing chemicals that will break down the iron particles embedded in the finish. When working with rail dust remover, use the necessary safety equipment, including gloves and goggles. Follow the chemical manufacturer's directions closely because it may require special handling and disposal. If, upon inspection, some particles are still present, the various chemical manufacturer's processes can be repeated. After the removal process, small pits may remain in the clearcoat and can be corrected, in most cases, with a finesse/polish operation. Procedure 1. Move the vehicle to a cool shaded area and make sure that the vehicle surfaces are cool during the removal process. DO NOT PERFORM THE REMOVAL PROCESS IN DIRECT SUNLIGHT OR ON A VEHICLE WITH HOT OR WARM BODY PANELS. 2. Wash the vehicle with soap and water. Dry it immediately and clean the affected areas with a wax and grease remover. 3. Perform the removal process according to the chemical manufacturer's directions. Once the damage has been repaired, the final step involves a polishing process. Rail Dust Remover Manufacturers Use the chemical manufacturers listed below, or equivalent: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > Customer Interest: > 05-08-51-008C > Jun > 09 > Body - Bumps or Rust Colored Spots in Paint > Page 7542 Auto Magic(R) or Clay Magic(R) products available from: Auto Wax Company, Inc. 1275 Round Table Dr. Dallas, TX 75247 (800) 826-0828 (Toll-Free) or (214) 631-4000 (Local) Fax (214) 634-1342 www.automagic.com [email protected] E038 Fallout Gel or E038E Liquid Fallout Remover II available from: Valvoline Car Brite Company 1910 South State Avenue Indianapolis, In 46203 (800) 347-2439 (Toll Free) or (317) 788-9925 (Local) Fax (317) 788-9930 www.carbrite.com [email protected] *We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. If rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. Warranty Information (excluding Saab U.S. Models) Important Refer to the Policy & Procedures Manual, section 1.2.1.7 for detailed information regarding warranty coverage for this condition. Important In certain cases where the vehicle finish is severely damaged and the actual repair time exceeds the published time, the additional time should be submitted in the "Other Labor Hours" field. Warranty Information (Saab U.S. Models) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 05-08-51-008C > Jun > 09 > Body - Bumps or Rust Colored Spots in Paint Paint: All Technical Service Bulletins Body - Bumps or Rust Colored Spots in Paint TECHNICAL Bulletin No.: 05-08-51-008C Date: June 22, 2009 Subject: Bumps or Rust Colored Spots in Paint Due to Rail or Iron Dust (Remove Rail Dust) Models: 1994-2010 GM Passenger Cars and Trucks (Including Saturn) 2003-2010 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-08-51-008B (Section 08 - Body and Accessories). Condition Visible rust colored spots or bumps on a vehicle's paint surface from rail or iron dust. Cause Rail dust comes from tiny iron particles produced from the friction between train wheels and the tracks and gets deposited on the vehicle surfaces. Iron dust can get deposited on the surface if the vehicle is stored near any operation producing iron dust such as an iron ore yard. Either material can lay on top of, or become embedded in, the paint surface. Correction Because the severity of the condition varies, proper diagnosis of the damage is critical to the success of repairs. Diagnosis should be performed on horizontal surfaces (hood, roof, deck lid, pick up box, etc.) after the vehicle has been properly cleaned. There are two types of repair materials recommended to repair rail dust or iron dust: 1. GEL TYPE OXALIC ACID: - Has the characteristics of the liquid type oxalic acid but stays where you put it because of its gel consistency. 2. CLAY TYPE NON-ACID BASED: - Requires surface lubricant during use. - Has different grades available. Caution Rail dust remover (Oxalic Acid) is an acidic substance containing chemicals that will break down the iron particles embedded in the finish. When working with rail dust remover, use the necessary safety equipment, including gloves and goggles. Follow the chemical manufacturer's directions closely because it may require special handling and disposal. If, upon inspection, some particles are still present, the various chemical manufacturer's processes can be repeated. After the removal process, small pits may remain in the clearcoat and can be corrected, in most cases, with a finesse/polish operation. Procedure 1. Move the vehicle to a cool shaded area and make sure that the vehicle surfaces are cool during the removal process. DO NOT PERFORM THE REMOVAL PROCESS IN DIRECT SUNLIGHT OR ON A VEHICLE WITH HOT OR WARM BODY PANELS. 2. Wash the vehicle with soap and water. Dry it immediately and clean the affected areas with a wax and grease remover. 3. Perform the removal process according to the chemical manufacturer's directions. Once the damage has been repaired, the final step involves a polishing process. Rail Dust Remover Manufacturers Use the chemical manufacturers listed below, or equivalent: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 05-08-51-008C > Jun > 09 > Body - Bumps or Rust Colored Spots in Paint > Page 7548 Auto Magic(R) or Clay Magic(R) products available from: Auto Wax Company, Inc. 1275 Round Table Dr. Dallas, TX 75247 (800) 826-0828 (Toll-Free) or (214) 631-4000 (Local) Fax (214) 634-1342 www.automagic.com [email protected] E038 Fallout Gel or E038E Liquid Fallout Remover II available from: Valvoline Car Brite Company 1910 South State Avenue Indianapolis, In 46203 (800) 347-2439 (Toll Free) or (317) 788-9925 (Local) Fax (317) 788-9930 www.carbrite.com [email protected] *We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. If rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. Warranty Information (excluding Saab U.S. Models) Important Refer to the Policy & Procedures Manual, section 1.2.1.7 for detailed information regarding warranty coverage for this condition. Important In certain cases where the vehicle finish is severely damaged and the actual repair time exceeds the published time, the additional time should be submitted in the "Other Labor Hours" field. Warranty Information (Saab U.S. Models) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 08-08-51-002 > Mar > 08 > Body - TPO Fascia Cleaning Prior to Painting Paint: All Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 72-05-11 > Dec > 97 > Warranty - Rail Dust Removal & Chemical Spotting Labor Paint: All Technical Service Bulletins Warranty - Rail Dust Removal & Chemical Spotting Labor File In Section: Warranty Administration Bulletin No.: 72-05-11 Date: December, 1997 WARRANTY ADMINISTRATION Subject: Clarification of Rail Dust Removal (A5575-A5580) and Chemical Spotting (A5541-A5544) Labor Operations Models: All Past and Future Passenger Cars and Light Duty Trucks The purpose of this Warranty Administration Bulletin is to clarify the usage, limits and guidelines for the proper use of the above subject labor operations. The above subject labor operations were introduced to correct paint imperfections caused by fallout that occurred either during shipment to the dealer or within the first 12 months or 12,000 miles (20,000 kms) of vehicle ownership. GM vehicle owners are informed that although no defect in the factory applied paint causes this, GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by fallout condition within 12 months or 12,000 miles (20,000 kms) whichever occurs first. Effective with repair orders dated on or after December 1, 1997, labor operations A5575-A5580 Rail Dust Removal and A5541 through A5544 Chemical Spotting will be limited to within the first 12 months or 12,000 miles of the Base Vehicle Warranty (20,000 kms) whichever occurs first. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 63-17-07B > Jun > 97 > Paint - Basecoat/Clearcoat Paint Systems Specifications Paint: All Technical Service Bulletins Paint - Basecoat/Clearcoat Paint Systems Specifications File In Section: 10 - Body Bulletin No.: 63-17-07B Date: June, 1997 INFORMATION Subject: New Aftermarket Paint Specification (GM4901M) for Basecoat/Clearcoat Paint Systems (Rigid Exterior Surfaces) Models: 1993-97 Passenger Cars and Trucks This bulletin is being revised to provide additional information on approved paint systems (Attachment 1 added). Please discard Corporate Bulletin Number 63-17-07A (Section 10 - Body). A vehicle's appearance is important to any customer's perception of that vehicle's quality and value. Furthermore, when an exterior finish repair is made, the customer expects that repair to match the showroom finish. Based upon rigorous and exhaustive testing, General Motors has established an aftermarket refinish paint specification, known as GM4901M, which is listed in the GM Engineering Specifications Manual. Use this specification when selecting a paint system for General Motors vehicle warranty paint repairs. All major paint suppliers are involved and support this program. The booklet enclosed with Corporate Bulletin # 63-17-07, "GM Approved Refinish Materials", P/N GM4901 M-D, identifies the paint systems you may use. All approved products (including VOC-compliant) are listed in the "system" approach recommended by the individual manufacturer. This booklet will be updated periodically to ensure you are provided with the latest information on paint systems. GM and Paint Supplier training services encompass this new specification and can address any questions. All materials listed in the booklet fall under the current materials allowance. However, this may change as costs increase. With this program, it is our goal to ensure quality repairs. After all, skilled technicians using the right materials offer the only path to true customer enthusiasm. By adhering to the GM4901M Specification for Aftermarket Paint Repair Materials, you will ensure our customers only receive the best while maximizing your quality throughout on exterior finish repairs. When a meeting or training session is held in your area, be sure your team is represented. We look forward to your support for this program. Additional Information In the development of this paint specification, major paint suppliers were invited to submit materials for approval. The requirements of the program are included in the approved materials booklet referenced above, dated December, 1996. Important: As of 7-1-97, the BASF products listed on Attachment 1 are now approved for use. The approved suppliers are: ^ Akzo Nobel (Sikkens) ^ American Standox ^ BASF ^ DuPont ^ ICI Autocolor ^ Martin Senour ^ PPG ^ Sherwin Williams Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 63-17-07B > Jun > 97 > Paint - Basecoat/Clearcoat Paint Systems Specifications > Page 7561 ^ Spies Hecker Your Zone wholesale personnel, Training Centers, STG Field Service Engineers, and the approved suppliers have additional training materials that may answer your further questions. Use of these GM approved materials ensures the highest quality for maintaining customer satisfaction. The dealer or retailer must ensure that all refinish materials, including sublets, meet GM Specification GM4901-M. Use of materials (and associated application methods) that do not meet this GM standard may result in a review of claim(s) leading to chargeback(s), as specified in the Policies and Procedures manual, Article 1.4.17. The standards will be updated periodically and other suppliers may be added when new standards are released by the fall of 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 63-17-07B > Jun > 97 > Paint - Basecoat/Clearcoat Paint Systems Specifications > Page 7562 ATTACHMENT 1 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 531704 > Sep > 95 > Paint - Polishing And Swirl Mark Removal Paint: All Technical Service Bulletins Paint - Polishing And Swirl Mark Removal File in Section: 10 - Body Bulletin No. 53-17-04 Date: September, 1995 INFORMATION Subject: Polishing and Swirl Mark Removal Techniques for Basecoat/Clearcoat Paint Models: 1993-96 Passenger Cars and Trucks with Basecoat/Clearcoat This bulletin supersedes and cancels Corporate Bulletin Number 111702. Previous divisional publication numbers were: Buick 93-10-22 Cadillac T-93-104 Chevrolet 93-188-OB GM Canada 93-10-158 Oldsmobile 07-93-106 (Service Guild) Pontiac 93-10-28 Today's basecoat/clearcoat paint finishes are very different from materials used on vehicles in the 1980's. Materials, procedures and equipment which once worked well for polishing traditional finishes may not be acceptable for use on basecoat/clearcoat paint surfaces. The use of outdated materials, procedures and equipment may produce what appears to be acceptable results under shop lighting, but will be unacceptable to the owner when the finish is exposed to sunlight (typically, swirl marks). While the following information can be most helpful in the new car "prep" area, it should also be made available to the "used car" area and the collision/ paint repair area. KEEP THE VEHICLE CLEAN AND DRY; ^ Avoid washing vehicles in direct sunlight. ^ Avoid using strong soaps or chemical detergents. ^ Use "brush less" type automatic car wash equipment. ^ Avoid using products containing acids (unless specified to correct a condition such as "rail dust"). ^ Don't use brushes or brooms to remove snow or ice from vehicles in storage or on lots. ^ Cleaning agents and water should be dried promptly and not allowed to dry on the surface. ^ Standing rinse water should be dried promptly and not allowed to dry on the surface. ^ Drying with a soft chamois is recommended. DON'T CREATE A PROBLEM: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 531704 > Sep > 95 > Paint - Polishing And Swirl Mark Removal > Page 7567 ^ DO NOT polish vehicles unless a surface condition exists that can only be corrected by polishing (see chart). ^ If a surface condition does exist, the repair approach should be one of "less is best" (the very least it takes to correct the condition). ^ Avoid removing too much clearcoat (whenever possible, use paint gauges before, during, and after polishing). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 531704 > Sep > 95 > Paint - Polishing And Swirl Mark Removal > Page 7568 ^ Use ONLY the products recommended in this bulletin (or their equivalent). ^ Make sure that any power polishing equipment does not exceed the requirements in the polish manufacturer's recommendation or in the chart. FINAL STEP: The final step of the finesse/polish procedure is the removal of SWIRL MARKS. Swirl marks are defined as very fine scratches in a uniform circular direction that cause an optical distortion on the paint surface. Swirl marks may not be visible with shop lighting. They should be viewed in direct sunlight or under specific lights, i.e. Sodium Vapor (parking lot type lights). SWIRL MARK REMOVAL - To remove swirl marks, use an orbital polisher (DA) with speeds in the 1,500 to 2,000 RPM range. Apply a small amount of the appropriate material (see chart) to the swirl mark area. Use the pad on the random orbital buffer to spread the material evenly over polished area before buffing. When buffing, keep pad flat and constantly moving over the repair area. Polish with heavier pressure applied for 4-6 seconds, then polish with lighter pressure for 6-8 more seconds. Always blend or feather outer edges of repair spot. After buffing, the buffed areas should be inspected by the buffing person to ensure that the swirls are completely removed. If swirls are still present, rebuff as needed. Hand wipe the surface with a clean soft, non-scratching cloth and a 50/50 mixture of Isopropyl Alcohol and water. ^ DON'T USE WAX OR SILICONE-TYPE PRODUCTS TO HIDE SWIRL MARKS (this condition will reappear later and cause owner dissatisfaction). ^ Specific conditions on paint (environmental damage, rail dust, etc.) can be corrected by referring to previously published Service bulletins on those specific topics. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 331704 > Sep > 93 > Paint - Exterior Color Code & Cross Reference Paint: All Technical Service Bulletins Paint - Exterior Color Code & Cross Reference Group Ref.: Body Bulletin No.: 331704 Date: September, 1993 SUBJECT: PAINT INFORMATION MODELS: 1994 CHEVROLET PRODUCTS (Except GEO) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Technical Service Bulletins for Paint: > 331704 > Sep > 93 > Paint - Exterior Color Code & Cross Reference > Page 7573 The chart provides paint information on 1994 Chevrolet products, The paint types listed the models indicate the material the vehicle was manufactured with. See illustrations. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 08-08-51-002 > Mar > 08 > Body - TPO Fascia Cleaning Prior to Painting Paint: All Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 72-05-11 > Dec > 97 > Warranty - Rail Dust Removal & Chemical Spotting Labor Paint: All Technical Service Bulletins Warranty - Rail Dust Removal & Chemical Spotting Labor File In Section: Warranty Administration Bulletin No.: 72-05-11 Date: December, 1997 WARRANTY ADMINISTRATION Subject: Clarification of Rail Dust Removal (A5575-A5580) and Chemical Spotting (A5541-A5544) Labor Operations Models: All Past and Future Passenger Cars and Light Duty Trucks The purpose of this Warranty Administration Bulletin is to clarify the usage, limits and guidelines for the proper use of the above subject labor operations. The above subject labor operations were introduced to correct paint imperfections caused by fallout that occurred either during shipment to the dealer or within the first 12 months or 12,000 miles (20,000 kms) of vehicle ownership. GM vehicle owners are informed that although no defect in the factory applied paint causes this, GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by fallout condition within 12 months or 12,000 miles (20,000 kms) whichever occurs first. Effective with repair orders dated on or after December 1, 1997, labor operations A5575-A5580 Rail Dust Removal and A5541 through A5544 Chemical Spotting will be limited to within the first 12 months or 12,000 miles of the Base Vehicle Warranty (20,000 kms) whichever occurs first. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 63-17-07B > Jun > 97 > Paint - Basecoat/Clearcoat Paint Systems Specifications Paint: All Technical Service Bulletins Paint - Basecoat/Clearcoat Paint Systems Specifications File In Section: 10 - Body Bulletin No.: 63-17-07B Date: June, 1997 INFORMATION Subject: New Aftermarket Paint Specification (GM4901M) for Basecoat/Clearcoat Paint Systems (Rigid Exterior Surfaces) Models: 1993-97 Passenger Cars and Trucks This bulletin is being revised to provide additional information on approved paint systems (Attachment 1 added). Please discard Corporate Bulletin Number 63-17-07A (Section 10 - Body). A vehicle's appearance is important to any customer's perception of that vehicle's quality and value. Furthermore, when an exterior finish repair is made, the customer expects that repair to match the showroom finish. Based upon rigorous and exhaustive testing, General Motors has established an aftermarket refinish paint specification, known as GM4901M, which is listed in the GM Engineering Specifications Manual. Use this specification when selecting a paint system for General Motors vehicle warranty paint repairs. All major paint suppliers are involved and support this program. The booklet enclosed with Corporate Bulletin # 63-17-07, "GM Approved Refinish Materials", P/N GM4901 M-D, identifies the paint systems you may use. All approved products (including VOC-compliant) are listed in the "system" approach recommended by the individual manufacturer. This booklet will be updated periodically to ensure you are provided with the latest information on paint systems. GM and Paint Supplier training services encompass this new specification and can address any questions. All materials listed in the booklet fall under the current materials allowance. However, this may change as costs increase. With this program, it is our goal to ensure quality repairs. After all, skilled technicians using the right materials offer the only path to true customer enthusiasm. By adhering to the GM4901M Specification for Aftermarket Paint Repair Materials, you will ensure our customers only receive the best while maximizing your quality throughout on exterior finish repairs. When a meeting or training session is held in your area, be sure your team is represented. We look forward to your support for this program. Additional Information In the development of this paint specification, major paint suppliers were invited to submit materials for approval. The requirements of the program are included in the approved materials booklet referenced above, dated December, 1996. Important: As of 7-1-97, the BASF products listed on Attachment 1 are now approved for use. The approved suppliers are: ^ Akzo Nobel (Sikkens) ^ American Standox ^ BASF ^ DuPont ^ ICI Autocolor ^ Martin Senour ^ PPG ^ Sherwin Williams Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 63-17-07B > Jun > 97 > Paint - Basecoat/Clearcoat Paint Systems Specifications > Page 7587 ^ Spies Hecker Your Zone wholesale personnel, Training Centers, STG Field Service Engineers, and the approved suppliers have additional training materials that may answer your further questions. Use of these GM approved materials ensures the highest quality for maintaining customer satisfaction. The dealer or retailer must ensure that all refinish materials, including sublets, meet GM Specification GM4901-M. Use of materials (and associated application methods) that do not meet this GM standard may result in a review of claim(s) leading to chargeback(s), as specified in the Policies and Procedures manual, Article 1.4.17. The standards will be updated periodically and other suppliers may be added when new standards are released by the fall of 1997. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 63-17-07B > Jun > 97 > Paint - Basecoat/Clearcoat Paint Systems Specifications > Page 7588 ATTACHMENT 1 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 531704 > Sep > 95 > Paint - Polishing And Swirl Mark Removal Paint: All Technical Service Bulletins Paint - Polishing And Swirl Mark Removal File in Section: 10 - Body Bulletin No. 53-17-04 Date: September, 1995 INFORMATION Subject: Polishing and Swirl Mark Removal Techniques for Basecoat/Clearcoat Paint Models: 1993-96 Passenger Cars and Trucks with Basecoat/Clearcoat This bulletin supersedes and cancels Corporate Bulletin Number 111702. Previous divisional publication numbers were: Buick 93-10-22 Cadillac T-93-104 Chevrolet 93-188-OB GM Canada 93-10-158 Oldsmobile 07-93-106 (Service Guild) Pontiac 93-10-28 Today's basecoat/clearcoat paint finishes are very different from materials used on vehicles in the 1980's. Materials, procedures and equipment which once worked well for polishing traditional finishes may not be acceptable for use on basecoat/clearcoat paint surfaces. The use of outdated materials, procedures and equipment may produce what appears to be acceptable results under shop lighting, but will be unacceptable to the owner when the finish is exposed to sunlight (typically, swirl marks). While the following information can be most helpful in the new car "prep" area, it should also be made available to the "used car" area and the collision/ paint repair area. KEEP THE VEHICLE CLEAN AND DRY; ^ Avoid washing vehicles in direct sunlight. ^ Avoid using strong soaps or chemical detergents. ^ Use "brush less" type automatic car wash equipment. ^ Avoid using products containing acids (unless specified to correct a condition such as "rail dust"). ^ Don't use brushes or brooms to remove snow or ice from vehicles in storage or on lots. ^ Cleaning agents and water should be dried promptly and not allowed to dry on the surface. ^ Standing rinse water should be dried promptly and not allowed to dry on the surface. ^ Drying with a soft chamois is recommended. DON'T CREATE A PROBLEM: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 531704 > Sep > 95 > Paint - Polishing And Swirl Mark Removal > Page 7593 ^ DO NOT polish vehicles unless a surface condition exists that can only be corrected by polishing (see chart). ^ If a surface condition does exist, the repair approach should be one of "less is best" (the very least it takes to correct the condition). ^ Avoid removing too much clearcoat (whenever possible, use paint gauges before, during, and after polishing). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 531704 > Sep > 95 > Paint - Polishing And Swirl Mark Removal > Page 7594 ^ Use ONLY the products recommended in this bulletin (or their equivalent). ^ Make sure that any power polishing equipment does not exceed the requirements in the polish manufacturer's recommendation or in the chart. FINAL STEP: The final step of the finesse/polish procedure is the removal of SWIRL MARKS. Swirl marks are defined as very fine scratches in a uniform circular direction that cause an optical distortion on the paint surface. Swirl marks may not be visible with shop lighting. They should be viewed in direct sunlight or under specific lights, i.e. Sodium Vapor (parking lot type lights). SWIRL MARK REMOVAL - To remove swirl marks, use an orbital polisher (DA) with speeds in the 1,500 to 2,000 RPM range. Apply a small amount of the appropriate material (see chart) to the swirl mark area. Use the pad on the random orbital buffer to spread the material evenly over polished area before buffing. When buffing, keep pad flat and constantly moving over the repair area. Polish with heavier pressure applied for 4-6 seconds, then polish with lighter pressure for 6-8 more seconds. Always blend or feather outer edges of repair spot. After buffing, the buffed areas should be inspected by the buffing person to ensure that the swirls are completely removed. If swirls are still present, rebuff as needed. Hand wipe the surface with a clean soft, non-scratching cloth and a 50/50 mixture of Isopropyl Alcohol and water. ^ DON'T USE WAX OR SILICONE-TYPE PRODUCTS TO HIDE SWIRL MARKS (this condition will reappear later and cause owner dissatisfaction). ^ Specific conditions on paint (environmental damage, rail dust, etc.) can be corrected by referring to previously published Service bulletins on those specific topics. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 331704 > Sep > 93 > Paint - Exterior Color Code & Cross Reference Paint: All Technical Service Bulletins Paint - Exterior Color Code & Cross Reference Group Ref.: Body Bulletin No.: 331704 Date: September, 1993 SUBJECT: PAINT INFORMATION MODELS: 1994 CHEVROLET PRODUCTS (Except GEO) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > 331704 > Sep > 93 > Paint - Exterior Color Code & Cross Reference > Page 7599 The chart provides paint information on 1994 Chevrolet products, The paint types listed the models indicate the material the vehicle was manufactured with. See illustrations. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > Page 7600 Paint: By Symptom Technical Service Bulletin # 05-08-51-008C Date: 090622 Body - Bumps or Rust Colored Spots in Paint TECHNICAL Bulletin No.: 05-08-51-008C Date: June 22, 2009 Subject: Bumps or Rust Colored Spots in Paint Due to Rail or Iron Dust (Remove Rail Dust) Models: 1994-2010 GM Passenger Cars and Trucks (Including Saturn) 2003-2010 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-08-51-008B (Section 08 - Body and Accessories). Condition Visible rust colored spots or bumps on a vehicle's paint surface from rail or iron dust. Cause Rail dust comes from tiny iron particles produced from the friction between train wheels and the tracks and gets deposited on the vehicle surfaces. Iron dust can get deposited on the surface if the vehicle is stored near any operation producing iron dust such as an iron ore yard. Either material can lay on top of, or become embedded in, the paint surface. Correction Because the severity of the condition varies, proper diagnosis of the damage is critical to the success of repairs. Diagnosis should be performed on horizontal surfaces (hood, roof, deck lid, pick up box, etc.) after the vehicle has been properly cleaned. There are two types of repair materials recommended to repair rail dust or iron dust: 1. GEL TYPE OXALIC ACID: - Has the characteristics of the liquid type oxalic acid but stays where you put it because of its gel consistency. 2. CLAY TYPE NON-ACID BASED: - Requires surface lubricant during use. - Has different grades available. Caution Rail dust remover (Oxalic Acid) is an acidic substance containing chemicals that will break down the iron particles embedded in the finish. When working with rail dust remover, use the necessary safety equipment, including gloves and goggles. Follow the chemical manufacturer's directions closely because it may require special handling and disposal. If, upon inspection, some particles are still present, the various chemical manufacturer's processes can be repeated. After the removal process, small pits may remain in the clearcoat and can be corrected, in most cases, with a finesse/polish operation. Procedure 1. Move the vehicle to a cool shaded area and make sure that the vehicle surfaces are cool during the removal process. DO NOT PERFORM THE REMOVAL PROCESS IN DIRECT SUNLIGHT OR ON A VEHICLE WITH HOT OR WARM BODY PANELS. 2. Wash the vehicle with soap and water. Dry it immediately and clean the affected areas with a wax and grease remover. 3. Perform the removal process according to the chemical manufacturer's directions. Once the damage has been repaired, the final step involves a polishing process. Rail Dust Remover Manufacturers Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > Page 7601 Use the chemical manufacturers listed below, or equivalent: Auto Magic(R) or Clay Magic(R) products available from: Auto Wax Company, Inc. 1275 Round Table Dr. Dallas, TX 75247 (800) 826-0828 (Toll-Free) or (214) 631-4000 (Local) Fax (214) 634-1342 www.automagic.com [email protected] E038 Fallout Gel or E038E Liquid Fallout Remover II available from: Valvoline Car Brite Company 1910 South State Avenue Indianapolis, In 46203 (800) 347-2439 (Toll Free) or (317) 788-9925 (Local) Fax (317) 788-9930 www.carbrite.com [email protected] *We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. If rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. Warranty Information (excluding Saab U.S. Models) Important Refer to the Policy & Procedures Manual, section 1.2.1.7 for detailed information regarding warranty coverage for this condition. Important In certain cases where the vehicle finish is severely damaged and the actual repair time exceeds the published time, the additional time should be submitted in the "Other Labor Hours" field. Warranty Information (Saab U.S. Models) Disclaimer Technical Service Bulletin # 05-08-51-008C Date: 090622 Body - Bumps or Rust Colored Spots in Paint Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > Page 7602 TECHNICAL Bulletin No.: 05-08-51-008C Date: June 22, 2009 Subject: Bumps or Rust Colored Spots in Paint Due to Rail or Iron Dust (Remove Rail Dust) Models: 1994-2010 GM Passenger Cars and Trucks (Including Saturn) 2003-2010 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-08-51-008B (Section 08 - Body and Accessories). Condition Visible rust colored spots or bumps on a vehicle's paint surface from rail or iron dust. Cause Rail dust comes from tiny iron particles produced from the friction between train wheels and the tracks and gets deposited on the vehicle surfaces. Iron dust can get deposited on the surface if the vehicle is stored near any operation producing iron dust such as an iron ore yard. Either material can lay on top of, or become embedded in, the paint surface. Correction Because the severity of the condition varies, proper diagnosis of the damage is critical to the success of repairs. Diagnosis should be performed on horizontal surfaces (hood, roof, deck lid, pick up box, etc.) after the vehicle has been properly cleaned. There are two types of repair materials recommended to repair rail dust or iron dust: 1. GEL TYPE OXALIC ACID: - Has the characteristics of the liquid type oxalic acid but stays where you put it because of its gel consistency. 2. CLAY TYPE NON-ACID BASED: - Requires surface lubricant during use. - Has different grades available. Caution Rail dust remover (Oxalic Acid) is an acidic substance containing chemicals that will break down the iron particles embedded in the finish. When working with rail dust remover, use the necessary safety equipment, including gloves and goggles. Follow the chemical manufacturer's directions closely because it may require special handling and disposal. If, upon inspection, some particles are still present, the various chemical manufacturer's processes can be repeated. After the removal process, small pits may remain in the clearcoat and can be corrected, in most cases, with a finesse/polish operation. Procedure 1. Move the vehicle to a cool shaded area and make sure that the vehicle surfaces are cool during the removal process. DO NOT PERFORM THE REMOVAL PROCESS IN DIRECT SUNLIGHT OR ON A VEHICLE WITH HOT OR WARM BODY PANELS. 2. Wash the vehicle with soap and water. Dry it immediately and clean the affected areas with a wax and grease remover. 3. Perform the removal process according to the chemical manufacturer's directions. Once the damage has been repaired, the final step involves a polishing process. Rail Dust Remover Manufacturers Use the chemical manufacturers listed below, or equivalent: Auto Magic(R) or Clay Magic(R) products available from: Auto Wax Company, Inc. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Paint, Striping and Decals > Paint > System Information > Technical Service Bulletins > All Other Service Bulletins for Paint: > Page 7603 1275 Round Table Dr. Dallas, TX 75247 (800) 826-0828 (Toll-Free) or (214) 631-4000 (Local) Fax (214) 634-1342 www.automagic.com [email protected] E038 Fallout Gel or E038E Liquid Fallout Remover II available from: Valvoline Car Brite Company 1910 South State Avenue Indianapolis, In 46203 (800) 347-2439 (Toll Free) or (317) 788-9925 (Local) Fax (317) 788-9930 www.carbrite.com [email protected] *We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. If rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. Warranty Information (excluding Saab U.S. Models) Important Refer to the Policy & Procedures Manual, section 1.2.1.7 for detailed information regarding warranty coverage for this condition. Important In certain cases where the vehicle finish is severely damaged and the actual repair time exceeds the published time, the additional time should be submitted in the "Other Labor Hours" field. Warranty Information (Saab U.S. Models) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Control Module > Component Information > Locations > Door Lock Delay Module Power Door Lock Control Module: Locations Door Lock Delay Module Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Control Module > Component Information > Locations > Door Lock Delay Module > Page 7609 Liftgate Wiring - RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear > Page 7614 Power Door Lock Relay: Locations Door Lock Delay Relay Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Defogger Timer Relay, Rear > Page 7615 Power Door Lock Relay: Locations Door Lock Relay Crossbody Harness Behind the right hand side of the ignition panel, at the top of the cowl. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Diagrams > Door Lock Delay Relay C201A, Door Lock Delay Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Diagrams > Door Lock Delay Relay > Page 7618 Power Door Lock Relay: Diagrams Door Lock Relay C241, Door Lock Relay C204A, Power Door Lock Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Roof and Associated Components > Sun Shade > Component Information > Technical Service Bulletins > Sunshade - Replacement Availability Sun Shade: Technical Service Bulletins Sunshade - Replacement Availability File In Section: 08 - Body and Accessories Bulletin No.: 99-08-110-005 Date: June, 1999 INFORMATION Subject: Sunshade Replacement Models: 1999 and Prior Chevrolet and GMC Light Duty Trucks This bulletin is to inform dealers that new replacement sunshades are being introduced for service on approximately July 19, 1999. These new replacement sunshades will no longer have the map strap feature. The part numbers for these replacement sunshades will remain the same as the previous parts. Once these new sunshades become available, current replacement sunshades on hand may be used at the customer's/dealer's discretion. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Head Rest > Component Information > Technical Service Bulletins > Recalls for Head Rest: > NHTSA94V177000 > Sep > 94 > Recall 94V177000: Seat Back Head Restraint Defect Head Rest: Recalls Recall 94V177000: Seat Back Head Restraint Defect THE FRONT DRIVER AND PASSENGER SEAT BACK HEIGHT DOES NOT CONFORM TO THE REQUIREMENTS OF FMVSS NO. 202, "HEAD RESTRAINTS." CONSEQUENCE OF NON-COMPLIANCE: SEAT OCCUPANTS ARE SUBJECT TO INCREASED RISK OF INJURY IN THE EVENT OF A SUDDEN STOP OR ACCIDENT. SHERRY DESIGNS WILL PROVIDE AN ATTACHABLE HEADREST FOR THE DEALER OR CUSTOMER TO ADD TO THE SEATS. SYSTEM: INTERIOR SYSTEMS; SEAT HEAD RESTRAINTS. VEHICLE DESCRIPTION: CONVERSION VANS. NOTE: IF THE VEHICLE IS PRESENTED TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND THE REMEDY IS NOT PROVIDED FREE OF CHARGE WITHIN A REASONABLE TIME OR THE REMEDY DOES NOT CORRECT THE NON-COMPLIANCE, PLEASE CONTACT SHERRY DESIGNS AT 1-219-264-0602. ALSO, CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-800-424-9393. 1992 CHEVROLET TRUCK ASTRO 1992 CHEVROLET TRUCK G20 1992 DODGE TRUCK B250 1993 CHEVROLET TRUCK ASTRO 1993 CHEVROLET TRUCK G20 1993 DODGE TRUCK B250 1994 CHEVROLET TRUCK ASTRO 1994 CHEVROLET TRUCK G20 1994 DODGE TRUCK B250 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Head Rest > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Head Rest: > NHTSA94V177000 > Sep > 94 > Recall 94V177000: Seat Back Head Restraint Defect Head Rest: All Technical Service Bulletins Recall 94V177000: Seat Back Head Restraint Defect THE FRONT DRIVER AND PASSENGER SEAT BACK HEIGHT DOES NOT CONFORM TO THE REQUIREMENTS OF FMVSS NO. 202, "HEAD RESTRAINTS." CONSEQUENCE OF NON-COMPLIANCE: SEAT OCCUPANTS ARE SUBJECT TO INCREASED RISK OF INJURY IN THE EVENT OF A SUDDEN STOP OR ACCIDENT. SHERRY DESIGNS WILL PROVIDE AN ATTACHABLE HEADREST FOR THE DEALER OR CUSTOMER TO ADD TO THE SEATS. SYSTEM: INTERIOR SYSTEMS; SEAT HEAD RESTRAINTS. VEHICLE DESCRIPTION: CONVERSION VANS. NOTE: IF THE VEHICLE IS PRESENTED TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND THE REMEDY IS NOT PROVIDED FREE OF CHARGE WITHIN A REASONABLE TIME OR THE REMEDY DOES NOT CORRECT THE NON-COMPLIANCE, PLEASE CONTACT SHERRY DESIGNS AT 1-219-264-0602. ALSO, CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-800-424-9393. 1992 CHEVROLET TRUCK ASTRO 1992 CHEVROLET TRUCK G20 1992 DODGE TRUCK B250 1993 CHEVROLET TRUCK ASTRO 1993 CHEVROLET TRUCK G20 1993 DODGE TRUCK B250 1994 CHEVROLET TRUCK ASTRO 1994 CHEVROLET TRUCK G20 1994 DODGE TRUCK B250 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Head Restraint System > System Information > Technical Service Bulletins > Restraints - Driver/Passenger Seat Head Rest Information Head Restraint System: Technical Service Bulletins Restraints - Driver/Passenger Seat Head Rest Information INFORMATION Bulletin No.: 10-08-50-003A Date: March 24, 2011 Subject: Information on Driver or Passenger Seat Head Restraint Concerns with Comfort, Custom Upholstery or Other Comfort Enhancing Devices Models: 2012 and Prior GM Passenger Cars and Trucks Equipped with Adjustable Head Restraints Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 10-08-50-003 (Section 08 - Body and Accessories). Important ON A GM VEHICLE EQUIPPED WITH ADJUSTABLE HEAD RESTRAINTS, USE THE HEAD RESTRAINT COVERS, FOAM AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER OR REPOSITION THE HEAD RESTRAINT SYSTEM. ANY ALTERATIONS TO HEAD RESTRAINTS DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER DESIGN ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. You may have a customer with a concern that the head restraint is uncomfortable or sits too far forward. The front driver and passenger seats are equipped with head restraints that have been designed to help minimize injuries while still providing comfort to the occupants. Each GM vehicle has its own specifically designed head restraint. The head restraints should only be used in the vehicle for which they were designed. The head restraint will not operate to its design intent if the original foam is replaced (1) by non-GM foam or head restraint, (2) by GM foam or head restraint designed for a different vehicle, (3) by GM foam or head restraint that has been altered by a trim shop or (4) if any object, such as an aftermarket comfort enhancing pad or device, is installed. Never modify the design of the head restraint or remove the head restraint from the vehicle as this may interfere with the operation of the seating and restraint systems and may prevent proper positioning of the passenger within the vehicle. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Power Seat Motor > Component Information > Diagrams > Driver's Forward/Rearward Motor C323, Driver's Forward/Rearward Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Power Seat Motor > Component Information > Diagrams > Driver's Forward/Rearward Motor > Page 7646 Power Seat Motor: Diagrams Driver's Tilt Motor C322, Driver's Front Tilt Motor C324, Driver's Rear Tilt Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Power Seat Switch > Component Information > Locations Power Seat And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Power Seat Switch > Component Information > Locations > Page 7650 C321, Driver's Seat Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Back > Component Information > Technical Service Bulletins > Recalls for Seat Back: > NHTSA94V177000 > Sep > 94 > Recall 94V177000: Seat Back Head Restraint Defect Seat Back: Recalls Recall 94V177000: Seat Back Head Restraint Defect THE FRONT DRIVER AND PASSENGER SEAT BACK HEIGHT DOES NOT CONFORM TO THE REQUIREMENTS OF FMVSS NO. 202, "HEAD RESTRAINTS." CONSEQUENCE OF NON-COMPLIANCE: SEAT OCCUPANTS ARE SUBJECT TO INCREASED RISK OF INJURY IN THE EVENT OF A SUDDEN STOP OR ACCIDENT. SHERRY DESIGNS WILL PROVIDE AN ATTACHABLE HEADREST FOR THE DEALER OR CUSTOMER TO ADD TO THE SEATS. SYSTEM: INTERIOR SYSTEMS; SEAT HEAD RESTRAINTS. VEHICLE DESCRIPTION: CONVERSION VANS. NOTE: IF THE VEHICLE IS PRESENTED TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND THE REMEDY IS NOT PROVIDED FREE OF CHARGE WITHIN A REASONABLE TIME OR THE REMEDY DOES NOT CORRECT THE NON-COMPLIANCE, PLEASE CONTACT SHERRY DESIGNS AT 1-219-264-0602. ALSO, CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-800-424-9393. 1992 CHEVROLET TRUCK ASTRO 1992 CHEVROLET TRUCK G20 1992 DODGE TRUCK B250 1993 CHEVROLET TRUCK ASTRO 1993 CHEVROLET TRUCK G20 1993 DODGE TRUCK B250 1994 CHEVROLET TRUCK ASTRO 1994 CHEVROLET TRUCK G20 1994 DODGE TRUCK B250 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Back > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Seat Back: > NHTSA94V177000 > Sep > 94 > Recall 94V177000: Seat Back Head Restraint Defect Seat Back: All Technical Service Bulletins Recall 94V177000: Seat Back Head Restraint Defect THE FRONT DRIVER AND PASSENGER SEAT BACK HEIGHT DOES NOT CONFORM TO THE REQUIREMENTS OF FMVSS NO. 202, "HEAD RESTRAINTS." CONSEQUENCE OF NON-COMPLIANCE: SEAT OCCUPANTS ARE SUBJECT TO INCREASED RISK OF INJURY IN THE EVENT OF A SUDDEN STOP OR ACCIDENT. SHERRY DESIGNS WILL PROVIDE AN ATTACHABLE HEADREST FOR THE DEALER OR CUSTOMER TO ADD TO THE SEATS. SYSTEM: INTERIOR SYSTEMS; SEAT HEAD RESTRAINTS. VEHICLE DESCRIPTION: CONVERSION VANS. NOTE: IF THE VEHICLE IS PRESENTED TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND THE REMEDY IS NOT PROVIDED FREE OF CHARGE WITHIN A REASONABLE TIME OR THE REMEDY DOES NOT CORRECT THE NON-COMPLIANCE, PLEASE CONTACT SHERRY DESIGNS AT 1-219-264-0602. ALSO, CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-800-424-9393. 1992 CHEVROLET TRUCK ASTRO 1992 CHEVROLET TRUCK G20 1992 DODGE TRUCK B250 1993 CHEVROLET TRUCK ASTRO 1993 CHEVROLET TRUCK G20 1993 DODGE TRUCK B250 1994 CHEVROLET TRUCK ASTRO 1994 CHEVROLET TRUCK G20 1994 DODGE TRUCK B250 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Cover > Component Information > Technical Service Bulletins > Interior - Seat Cover Wrinkle/Crease/Burn Info Seat Cover: Technical Service Bulletins Interior - Seat Cover Wrinkle/Crease/Burn Info INFORMATION Bulletin No.: 04-08-50-006D Date: September 09, 2010 Subject: Minor Wrinkles/Creases, Discoloration, Cigarette Burns and Customer Induced Cuts and Stains on Front and Rear Driver and Passenger Seats with Leather, Vinyl or Cloth Seat Covers Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2009 and Prior Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add a model year. Please discard Corporate Bulletin Number 04-08-50-006C (Section 08 - Body and Accessories). If a customer comes in to your dealership due to certain conditions of the seat covers (splits, wrinkles, loose stitching, etc.), you must examine the seat cover in order to determine the validity of the customer claim. Some components from the above listed vehicles have been returned to the Warranty Parts Center (WPC) and analysis of these parts showed "customer induced damage" or No Trouble Found (NTF). The dealer should pay particular attention to the following conditions: - Cigarette burns Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Cover > Component Information > Technical Service Bulletins > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 7668 - Customer induced cuts (knife cuts, cut by customer tools, etc.) - Paint stains (customer should have cleaned paint stains while paint was still wet) - Coffee stains and other removable dirt These should be cleaned as described in the Owner's Manual under Appearance Care. Also, refer to Corporate Bulletin Number 06-00-89-029A or later. - Evidence of chemicals used for cleaning, other than those specified in the Owner's Manual - Other chemical spills - Minor and normal leather wrinkles as a result of use - Other defects to the seat cover not detected during the pre-delivery inspection (PDI). Inform the customer that the above issues were not present when the vehicle was purchased and cannot be replaced under warranty. The covers, however, may be repaired or replaced at the customer's expense. The following conditions are not caused by the customer and should be covered by warranty: - Split seams Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Cover > Component Information > Technical Service Bulletins > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 7669 - Wear/cracking/peeling - Discoloration/dye transfer from customer clothing (if discoloration/dye transfer is not removed after using GM Leather and Vinyl Plastic Cleaner, P/N 88861401 (in Canada, P/N 88861409), replace the covers.) Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Cover > Component Information > Technical Service Bulletins > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 7670 Seat Cover: Technical Service Bulletins Interior - Elimination Of Unwanted Odors INFORMATION Bulletin No.: 00-00-89-027E Date: September 29, 2008 Subject: Eliminating Unwanted Odors in Vehicles Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and refine the instructions. Please discard Corporate Bulletin Number 00-00-89-027D (Section 00 - General Information). Vehicle Odor Elimination General Motors offers a product that may control or eliminate odors in the interior and luggage compartment areas of GM vehicles. GM Vehicle Care Odor Eliminator is a non-toxic, biodegradable odor remover. This odorless product has been shown to greatly reduce or remove objectionable smells of mold and mildew resulting from vehicle water leaks (as well as customer created odors, i.e. smoke). You may use GM Vehicle Care Odor Eliminator on fabrics, vinyl, leather, carpet and sound deadening materials. It may also be induced into HVAC modules and instrument panel ducts (for the control of non-bacterial related odors). Important: This product leaves no residual scent and should not be sold as or considered an air freshener. Product action may result in the permanent elimination of an odor and may be preferable to customers with allergies who are sensitive to perfumes. How to Use This Product GM Vehicle Care Odor Eliminator may be sprayed on in a ready-to-use formula or used in steam cleaners as an additive with carpet shampoo. This water-based, odorless product is safe for all vehicle interiors. Do not wet or soak any interior surface that plain water would cause to deteriorate, as this product will have the same effect. Also avoid letting this product come into contact with vinegar or any acidic substance. Acid-based products will hamper the effectiveness of, or render GM Vehicle Care Odor Eliminator inert. Note: Complete eight page treatment sheets are enclosed within each case of GM Vehicle Care Odor Eliminator. These treatment instructions range from simple vehicle odor elimination to full step by step procedures for odor removal from water leaks. If lost, contact 800-977-4145 to get a replacement set faxed or e-mailed to your dealership. Instructions and cautions are printed on the bottle, but additional help is available. If you encounter a difficult to eliminate or reoccurring odor, you may call 1-800-955-8591 (in Canada, 1-800-977-4145) to obtain additional information and usage suggestions. Important: This product may effectively remove odors when directly contacting the odor source. It should be used in conjunction with diagnostic procedures (in cases such as a water leak) to first eliminate the root cause of the odor, and then the residual odor to permanently correct the vehicle condition. Vehicle Waterleak Odor Elimination STEP ONE: Confirm that all water leaks have been repaired. Determine what areas of the vehicle were water soaked or wet. Components with visible mold/mildew staining should be replaced. Isolate the odor source inside the vehicle. Often an odor can be isolated to an area or component of the vehicle interior by careful evaluation. Odor evaluation may need to be performed by multiple persons. Another method of isolating an odor source is to remove and segregate interior trim and components. Plastic sheeting or drop cloths can be used to confine seats, headliners, etc. to assist in evaluation and diagnoses. If appropriate the vehicle and interior trim should be evaluated separately to determine if the odor stays with the vehicle or the interior components. Odors that stay with the vehicle may be isolated to insulating and sound deadening materials (i.e. water leak at the windshield or standing water in the front foot well area caused mold/mildew to form on the bulkhead or kick panel sound deadening pads. If the interior is removed the floor pan and primed/painted surfaces should be treated with bleach/soap solution, rinsed with clean water and dried. Interior surfaces should then be treated with GM Vehicle Care Odor Eliminator product before reinstalling carpet or reassembling. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Cover > Component Information > Technical Service Bulletins > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 7671 The GM Vehicle Care Odor Eliminator product is an effective odor elimination product when used properly. It must come into direct contact with the odor source. It should be used in conjunction with diagnostic procedures to first eliminate the root cause of the odor. Some procedures for use after odor root cause correction are: STEP TWO: ^ Use the trigger spray head. ^ Put a drop of dish soap the size of a quarter in the bottom of a bottle. ^ Add 8 oz. of GM Vehicle Care Odor Eliminator (1 cup) to the dish soap and top off the bottle with tap water. ^ This formula should be used on hard surfaces (dash, interior plastic molding, and floor pan) STEP THREE: The third step to neutralizing the vehicle is a light to medium treatment of all carpeting and upholstered seats with the GM Vehicle Care Odor Eliminator formula and a wide fan spray setting (at full strength) (i.e.: carpeting on the driver's side requires 4-5 triggers pulls for coverage). The headliner and trunk should be sprayed next. Lightly brushing the formula into the carpeting and upholstery is a recommended step for deep odor problems. The dash and all hard surfaces should be sprayed with dish soap/water mixture. Let stand for 1-2 minutes then wipe off the surface. STEP FOUR: (vehicle ventilation system treatment) The ventilation system is generally the last step in the treatment of the vehicle. a. Spray the GM Vehicle Care Odor Eliminator formula into all dash vents. (1-2 trigger pulls per vent). b. Start the vehicle and turn the vehicle fan on high cool (not A/C setting). c. Spray the formula (10 trigger pulls) into the outside fresh air intake vent (cowl at base of windshield) d. Enter the vehicle after 1 minute and wipe off the excess formula spurting out of the dash vents. e. Smell the air coming from the dash vents. If odors are still present, spray another 5 triggers into the cowl, wait another minute and smell the results. Once you have obtained a fresh, clean smell coming from the vents, turn the system to the A/C re-circulation setting. Roll up the windows, spray 3-5 pumps into the right lower IP area and let the vehicle run with the fan set on high for 5-7 minutes. Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. Additional Suggestions to Increase Customer Satisfaction Here are some additional ideas to benefit your dealership and to generate greater customer enthusiasm for this product. ^ Keep this product on-hand for both the Service Department and the Used Car lot. Add value to your used car trades; treat loaner and demo cars during service and at final sale to eliminate smoke, pet, and other common odors offensive to customers. Make deodorizing a vehicle part of your normal vehicle detailing service. ^ Consider including GM Vehicle Care Odor Eliminator as a give-away item with new vehicle purchases. Many dealers give away as "gifts" various cleaning supplies at time of delivery. GM Odor Eliminator is one of a few products GM offers that has as many uses in the home as in the vehicle. Customers may find this product can be used for a host of recreational activities associated with their new vehicle, such as deodorizing a boat they tow, or a camper. ^ GM Odor Eliminator and many of the GM Vehicle Care products offer you the chance to increase dealership traffic as these superior quality products cannot be purchased in stores. Many Dealerships have product displays at the parts counter. Consider additional displays in the Customer Service Lounge, the Showroom and at the Service Desk or Cashier Window. Many customers who purchase vehicles and receive regular maintenance at your dealership may never visit the parts counter, and subsequently are not exposed to the variety and value that these products offer. Parts Information Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Seats > Seat Cover > Component Information > Technical Service Bulletins > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 7672 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Component Locations Power Door Lock Switch: Component Locations Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Component Locations > Page 7678 RH Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Component Locations > Page 7679 Door Wiring W/Power Door Locks Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Page 7680 Power Door Lock Switch: Diagrams C604, Front RH Power Door Lock Switch C504, Front Door Lock Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Locations > Component Locations Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Locations > Component Locations > Page 7685 Power Mirror Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch C248, Crossbody To Mirror Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch > Page 7688 C275, Power Mirror Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Diagrams > Crossbody to Mirror Switch > Page 7689 C248, Mirror Switch To Crossbody Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Locations Power Seat And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Locations > Page 7693 C321, Driver's Seat Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Locations > Compartment Lid Release Switch, Rear Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Locations > Compartment Lid Release Switch, Rear > Page 7698 Trunk / Liftgate Switch: Locations Liftgate Strut Switch Upper RH rear D-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear C203, Liftgate Release Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear > Page 7701 C918, Liftgate Key Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > Compartment Lid Release Switch, Rear > Page 7702 Trunk / Liftgate Switch: Diagrams Liftgate Strut Switch C417, Liftgate Strut Switch C417, Liftgate Strut Switch (Body Side) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Unibody > Cowl > Component Information > Locations Cowl: Locations Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Unibody > Cowl > Component Information > Locations > Page 7707 Crossbody Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > Customer Interest: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip Weatherstrip: Customer Interest Dutch Door - Water Leak at Weatherstrip File In Section: 10 - Body Bulletin No.: 46-15-02 Date: October, 1994 Subject: Dutch Door Water Leak at Center Weatherstrip (Install New Garnish Molding and Shim) Models: 1992-94 Chevrolet and GMC Truck M/L Vans with RPO E54 Shims and revised garnish moldings are currently being installed in production vehicles. Reference the following chart for specific vin breakpoints: GMC Chevrolet Shim RB502146 RB105463 Revised Molding RB541904 RB206312 Condition Some owners may comment that they are experiencing water leaks at the center top of the rear primary weatherstrip. For water leaks at a location other than the center of the weatherstrip, see Bulletin Number 361501. Cause The metal flange in this area may not be thick enough to properly allow the weatherstrip to adhere to it, or the liftgate interior garnish molding may be pushing the weatherstrip down into the vehicle instead of seating on the liftgate frame. Correction To repair this condition, it may be necessary to replace the liftgate interior garnish molding and add a shim near the center top of the liftgate flange. The shim will take up the slack at the centerline of the vehicle, allowing the weatherstrip to adhere properly. The new garnish molding has a revised trim line which will eliminate any interference between the molding and the weatherstrip. The service procedures are as follows: To add shim: 1. Remove the upper D-ring molding and disconnect the top center of the liftgate opening weatherstrip using 3M Release Agent (or equivalent) to break the bond of the weatherstrip adhesive. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > Customer Interest: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip > Page 7716 2. Attach the shim at the top center of the metal liftgate opening flange. The shim should be positioned on the forward side of the flange (Figure 1, Item A). The shim should be approximately 146 mm x 12.7 mm x 3 mm, made from an ABS material or equivalent, and adhered with 3M Weatherstrip Adhesive or equivalent. 3. Reconnect the weatherstrip to the flange using 3M Weatherstrip Adhesive or equivalent. 4. Reinstall the upper D-ring molding. To replace garnish molding: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > Customer Interest: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip > Page 7717 1. At the liftgate garnish molding, remove the interior handle screw covers (Figure 2, Item A). 2. Remove the screws which secure the liftgate handle (Figure 2, Item B). 3. Remove the liftgate handle (Figure 2, Item C) and escutcheon (Figure 2, Item D). 4. Remove the screws which secure the liftgate garnish molding (Figure 2, Item E) to the liftgate assembly (Figure 2, Item F), and remove the molding. 5. Install the new liftgate garnish molding, tightening the garnish molding screws to 1.4 N-m (12 lb.in.). 6. Reinstall the liftgate handle and escutcheon. 7. Reinstall the screws which secure the liftgate handle and tighten to 6 N-m (53 lb.in.). B. Reinstall the interior handle screw covers. Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > Customer Interest: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip > Page 7718 Warranty Information For vehicles repaired under warranty, use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Weatherstrip: > 99-08-64-016C > Jul > 09 > Body - Maintaining Exterior Weatherstrip Appearance Weatherstrip: All Technical Service Bulletins Body - Maintaining Exterior Weatherstrip Appearance INFORMATION Bulletin No.: 99-08-64-016C Date: July 29, 2009 Subject: Information on Maintaining Exterior Weatherstrip Appearance Models: 2010 and Prior Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and update the parts and procedure information. Please discard Corporate Bulletin Number 99-08-64-016B (Section 08 - Body and Accessories). Exterior weatherstrips are exposed to a variety of environmental elements, including UV rays, acid rain, insect and bird residue and atmospheric fallout. All of these may effect the appearance of the weatherstrips; however, they do not effect the functionality of the weatherstrip. Weatherstrips that are discolored should not be replaced under the normal GM New Vehicle Warranty. Weatherstrip Maintenance Instructions Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Clean the weatherstrips with a mild soap and water solution. Apply silicone grease with a clean cloth. During very cold, damp weather, frequent application may be required. Refer to the information below for the recommended maintenance products. Weatherstrips that are not maintained may crack and weather due to environmental elements. Parts Information Weatherstrip Conditioning Weatherstrip Lubricant (GM P/N 3634770 [in Canada, P/N 10953518]) or Dielectric Silicone Grease (GM P/N 12345579 [in Canada, P/N 992887]). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Weatherstrip: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip Weatherstrip: All Technical Service Bulletins Dutch Door - Water Leak at Weatherstrip File In Section: 10 - Body Bulletin No.: 46-15-02 Date: October, 1994 Subject: Dutch Door Water Leak at Center Weatherstrip (Install New Garnish Molding and Shim) Models: 1992-94 Chevrolet and GMC Truck M/L Vans with RPO E54 Shims and revised garnish moldings are currently being installed in production vehicles. Reference the following chart for specific vin breakpoints: GMC Chevrolet Shim RB502146 RB105463 Revised Molding RB541904 RB206312 Condition Some owners may comment that they are experiencing water leaks at the center top of the rear primary weatherstrip. For water leaks at a location other than the center of the weatherstrip, see Bulletin Number 361501. Cause The metal flange in this area may not be thick enough to properly allow the weatherstrip to adhere to it, or the liftgate interior garnish molding may be pushing the weatherstrip down into the vehicle instead of seating on the liftgate frame. Correction To repair this condition, it may be necessary to replace the liftgate interior garnish molding and add a shim near the center top of the liftgate flange. The shim will take up the slack at the centerline of the vehicle, allowing the weatherstrip to adhere properly. The new garnish molding has a revised trim line which will eliminate any interference between the molding and the weatherstrip. The service procedures are as follows: To add shim: 1. Remove the upper D-ring molding and disconnect the top center of the liftgate opening weatherstrip using 3M Release Agent (or equivalent) to break the bond of the weatherstrip adhesive. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Weatherstrip: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip > Page 7728 2. Attach the shim at the top center of the metal liftgate opening flange. The shim should be positioned on the forward side of the flange (Figure 1, Item A). The shim should be approximately 146 mm x 12.7 mm x 3 mm, made from an ABS material or equivalent, and adhered with 3M Weatherstrip Adhesive or equivalent. 3. Reconnect the weatherstrip to the flange using 3M Weatherstrip Adhesive or equivalent. 4. Reinstall the upper D-ring molding. To replace garnish molding: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Weatherstrip: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip > Page 7729 1. At the liftgate garnish molding, remove the interior handle screw covers (Figure 2, Item A). 2. Remove the screws which secure the liftgate handle (Figure 2, Item B). 3. Remove the liftgate handle (Figure 2, Item C) and escutcheon (Figure 2, Item D). 4. Remove the screws which secure the liftgate garnish molding (Figure 2, Item E) to the liftgate assembly (Figure 2, Item F), and remove the molding. 5. Install the new liftgate garnish molding, tightening the garnish molding screws to 1.4 N-m (12 lb.in.). 6. Reinstall the liftgate handle and escutcheon. 7. Reinstall the screws which secure the liftgate handle and tighten to 6 N-m (53 lb.in.). B. Reinstall the interior handle screw covers. Parts Information Parts are currently available from GMSPO. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Weatherstrip: > 461502 > Oct > 94 > Dutch Door - Water Leak at Weatherstrip > Page 7730 Warranty Information For vehicles repaired under warranty, use: Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Body and Frame > Weatherstrip > Component Information > Technical Service Bulletins > All Other Service Bulletins for Weatherstrip: > 99-08-64-016C > Jul > 09 > Body - Maintaining Exterior Weatherstrip Appearance Weatherstrip: All Technical Service Bulletins Body - Maintaining Exterior Weatherstrip Appearance INFORMATION Bulletin No.: 99-08-64-016C Date: July 29, 2009 Subject: Information on Maintaining Exterior Weatherstrip Appearance Models: 2010 and Prior Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and update the parts and procedure information. Please discard Corporate Bulletin Number 99-08-64-016B (Section 08 - Body and Accessories). Exterior weatherstrips are exposed to a variety of environmental elements, including UV rays, acid rain, insect and bird residue and atmospheric fallout. All of these may effect the appearance of the weatherstrips; however, they do not effect the functionality of the weatherstrip. Weatherstrips that are discolored should not be replaced under the normal GM New Vehicle Warranty. Weatherstrip Maintenance Instructions Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Clean the weatherstrips with a mild soap and water solution. Apply silicone grease with a clean cloth. During very cold, damp weather, frequent application may be required. Refer to the information below for the recommended maintenance products. Weatherstrips that are not maintained may crack and weather due to environmental elements. Parts Information Weatherstrip Conditioning Weatherstrip Lubricant (GM P/N 3634770 [in Canada, P/N 10953518]) or Dielectric Silicone Grease (GM P/N 12345579 [in Canada, P/N 992887]). Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 7740 C251, Cruise Control Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 7741 Brake Switch (Cruise Control): Description and Operation The brake switch is used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 7742 Brake Switch (Cruise Control): Adjustments With the brake pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams C254, Cruise Control Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Page 7746 Clutch Switch: Description and Operation The clutch switch is used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Page 7747 Clutch Switch: Adjustments With the clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: Customer Interest Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 7756 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: All Technical Service Bulletins Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 7762 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Other Service Bulletins for Cruise Control Module: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 7773 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 7774 C253, Cruise Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 7775 Cruise Control Module: Description and Operation The module monitors cruise control switch position, signals from the speed sensor, servo position and release switch operation, then operates vacuum valves within the servo unit to control servo operation and vehicle speed. The module also contains a speed limiting function which prevents system operation at speeds below approximately 25 mph. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Servo > Component Information > Locations > Component Locations Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Servo > Component Information > Locations > Component Locations > Page 7780 Cruise Control Servo Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Servo > Component Information > Locations > Page 7781 Cruise Control Servo: Description and Operation Fig. 2 Servo Assembly The servo, Fig. 2, consists of a vacuum operated diaphragm, a normally open solenoid valve to vent the diaphragm, a normally closed solenoid valve connecting the diaphragm chamber to the vacuum source, and a variable inductance position sensor that provides the module with servo position data. The servo operates the throttle in response to control module commands as follows: When the system is engaged and operating at a steady rate of speed, both solenoid valves are closed. Vacuum is trapped in the diaphragm chamber exerting a constant force on the diaphragm and the throttle position remains fixed. When the vehicle is losing speed due to increased load, or when the operator seeks to increase speed through the control switch assembly, the module energizes the vacuum valve solenoid. This increases the force exerted on the diaphragm, which in turn increases the throttle opening. When vehicle speed increases above the pre-set cruise speed, or when the operator seeks to decrease speed through the control switch assembly, the module de-energizes the diaphragm vent valve solenoid. This opens the valve, decreases force on the diaphragm, and allows the throttle return spring to decrease the throttle opening. During normal operation, the module will pulse the operation of the vent or vacuum valves, as needed, to maintain the set cruise speed. The average duration of each pulse is 10 milliseconds. If vehicle speed drops 5 mph below set cruise speed, the module will hold the vacuum valve in the completely open (energized) position. If vehicle speed exceeds set cruise speed by 3 mph or more, then module will hold the vent valve in the open (de-energized) position. The module will hold the valves open until the vehicle speed matches the set cruise speed. The diaphragm vent valve will also remain in the fully open position if the brake or clutch pedal is depressed, the ignition is switched off, or if an open circuit exists in the system feed circuit or in the servo position sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Servo Cable > Component Information > Adjustments Cruise Control Servo Cable: Adjustments 1. Ensure throttle is completely closed and ignition is off. 2. Adjust servo cable/linkage to .15-.39 inch clearance at throttle stud Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Switch > Component Information > Description and Operation Cruise Control Switch: Description and Operation Fig. 1 Cruise Control Switch The cruise control switch, Fig. 1, consists of a 3 position slide-type switch and a set/coast switch button. To operate the system, the slide switch must be in on position and vehicle speed must be above 25 mph. The system is engaged at the desired speed by fully depressing, then releasing the set/coast button. Cruise speed can be increased from set position by accelerating vehicle to desired speed, then pressing and releasing button. In order to decrease speed, the set/coast button is held in the fully depressed position (disengaging system), then released when the desired speed is reached. The system can be disengaged at any time by depressing the brake or clutch pedal, or by moving the slide switch to off position. If the system is disengaged by depressing the brake or clutch pedal, the last set speed will be retained in the module memory until the slide switch or ignition switch is moved to off position. Momentarily moving the slide switch to the resume/accel position will cause the vehicle to accelerate to the last set speed and maintain that speed. If the slide switch is held in the resume/accel position, the vehicle will continue to accelerate until the switch is released. When the switch is released, the speed that the vehicle accelerated to becomes the new set speed. The slide switch also allows a tap-up function to increase cruise set speed in 1 mph increments. With the cruise control engaged and operating, tapping-up is done by pressing the slide switch to the resume position, then quickly releasing it. This procedure can be repeated 10 times before the system must be reset to a new speed in the conventional manner. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Cruise Control Switch > Component Information > Description and Operation > Page 7788 Cruise Control Switch: Service and Repair 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect cruise control connector from main harness connector and attach a suitable length of flexible wire to cruise control harness. Fig. 10 Cruise Control Switch replacement 3. Tape joint between main and control harness to aid removal, then remove control assembly, Fig. 10. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: Customer Interest Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 7798 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: All Technical Service Bulletins Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 7804 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 7805 Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 7806 C253, Cruise Control Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 7807 Cruise Control Module: Description and Operation The module monitors cruise control switch position, signals from the speed sensor, servo position and release switch operation, then operates vacuum valves within the servo unit to control servo operation and vehicle speed. The module also contains a speed limiting function which prevents system operation at speeds below approximately 25 mph. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 7812 C251, Cruise Control Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 7813 Brake Switch (Cruise Control): Description and Operation The brake switch is used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Page 7814 Brake Switch (Cruise Control): Adjustments With the brake pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams C254, Cruise Control Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Page 7818 Clutch Switch: Description and Operation The clutch switch is used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Page 7819 Clutch Switch: Adjustments With the clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Description and Operation Cruise Control Switch: Description and Operation Fig. 1 Cruise Control Switch The cruise control switch, Fig. 1, consists of a 3 position slide-type switch and a set/coast switch button. To operate the system, the slide switch must be in on position and vehicle speed must be above 25 mph. The system is engaged at the desired speed by fully depressing, then releasing the set/coast button. Cruise speed can be increased from set position by accelerating vehicle to desired speed, then pressing and releasing button. In order to decrease speed, the set/coast button is held in the fully depressed position (disengaging system), then released when the desired speed is reached. The system can be disengaged at any time by depressing the brake or clutch pedal, or by moving the slide switch to off position. If the system is disengaged by depressing the brake or clutch pedal, the last set speed will be retained in the module memory until the slide switch or ignition switch is moved to off position. Momentarily moving the slide switch to the resume/accel position will cause the vehicle to accelerate to the last set speed and maintain that speed. If the slide switch is held in the resume/accel position, the vehicle will continue to accelerate until the switch is released. When the switch is released, the speed that the vehicle accelerated to becomes the new set speed. The slide switch also allows a tap-up function to increase cruise set speed in 1 mph increments. With the cruise control engaged and operating, tapping-up is done by pressing the slide switch to the resume position, then quickly releasing it. This procedure can be repeated 10 times before the system must be reset to a new speed in the conventional manner. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Cruise Control > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Description and Operation > Page 7823 Cruise Control Switch: Service and Repair 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect cruise control connector from main harness connector and attach a suitable length of flexible wire to cruise control harness. Fig. 10 Cruise Control Switch replacement 3. Tape joint between main and control harness to aid removal, then remove control assembly, Fig. 10. 4. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Air Conditioning Indicator Lamp > Component Information > Technical Service Bulletins > Customer Interest for Air Conditioning Indicator Lamp: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Air Conditioning Indicator Lamp > Component Information > Technical Service Bulletins > Customer Interest for Air Conditioning Indicator Lamp: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 7833 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Air Conditioning Indicator Lamp > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Conditioning Indicator Lamp: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Air Conditioning Indicator Lamp > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Conditioning Indicator Lamp: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 7839 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Air Conditioning Indicator Lamp > Component Information > Technical Service Bulletins > Page 7840 Air Conditioning Indicator Lamp: Locations In heater A/C control assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Locations > Audio Alarm Module Audible Warning Device: Locations Audio Alarm Module Convenience Center And Audio Alarm Module Instrument Panel Cluster Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Locations > Audio Alarm Module > Page 7845 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Locations > Page 7846 Audible Warning Device: Description and Operation The Warnings and Alarms System sounds a buzzer or chime to bring attention to one or more of several conditions. These conditions are: 1. The lamps are on and the Ignition Switch is turned to LOCK, OFF, or ACC. 2. The key is in the Ignition Switch when the driver's door is open. 3. The safety belt is unbuckled when Ignition Switch is in any position but OFF or ACC. Voltage is supplied at all times through the STOP-HZ Fuse through ORN (140) wire to supply voltage to the Audio Alarm Module. Ignition Key Warning Whenever the key is in the Ignition Switch, the Ignition Switch is in LOCK, OFF, or ACC, and the driver's door is open, the LT GRN (80) wire signals a ground to the Module. This sounds the alarm. Safety Belt Warning With the Ignition Switch in RUN or START, voltage is supplied through the GAGES fuse through PNK/BLK (39) wire to the Audio Alarm Module. With the driver's safety belt not buckled, the BLK (238) wire sends a ground signal to the module. The ground signal on the BLK (238) wire is also sent to the Diagnostic Energy Reserve module of the AIR BAG system. The Fasten Belts Indicator always goes on for about five seconds when the Ignition Switch is turned to RUN or START. Lights-On Warning (Chime Only) When the Light Switch is in HEAD or PARK and the Panel Dimmer Switch is not at the dimmest setting, voltage is supplied through the INSTR LPS Fuse to the Audio Alarm Module. With the Panel Dimmer Switch at its dimmest setting, the current to the Audio Alarm may not be enough to be sensed by the module. When the Ignition Switch is turned to RUN or START, voltage is supplied through the GAGES Fuse and the PNK/BLK (39) wire to the Module. These two voltages are sensed and the alarm is not sounded. When the Ignition Switch is turned to LOCK, OFF, or ACC, the GAGES Fuse loses voltage. The Audio Alarm Module senses the change. If voltage is still available from the INSTR LPS Fuse, voltage from the STOP-HZ Fuse is supplied to sound the alarm. The alarm can be turned off by turning the Light Switch off. The Module no longer senses voltage from the Light Switch, so the alarm does not sound. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Audible Warning Device: Initial Inspection and Diagnostic Overview Check condition of GAGES, INSTR LPS and STOP-HZ Fuse(s). If fuse(s) is blown, locate and repair source of overload. Replace fuse(s). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 7849 Audible Warning Device: Symptom Related Diagnostic Procedures Audio Alarm Does Not Operate Or Stays On All The Time (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 7850 Audio Alarm Does Not Operate Or Stays On All The Time (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 7851 Audible Warning Device: Component Tests and General Diagnostics The Warnings and Alarms System sounds a buzzer or chime to bring attention to one or more of several conditions. These conditions are: 1. The lamps are on and the Ignition Switch is turned to LOCK, OFF, or ACC. 2. The key is in the Ignition Switch when the driver's door is open. 3. The safety belt is unbuckled when Ignition Switch is in any position but OFF or ACC. Voltage is supplied at all times through the STOP-HZ Fuse through ORN (140) wire to supply voltage to the Audio Alarm Module. Ignition Key Warning Whenever the key is in the Ignition Switch, the Ignition Switch is in LOCK, OFF, or ACC, and the driver's door is open, the LT GRN (80) wire signals a ground to the Module. This sounds the alarm. Safety Belt Warning With the Ignition Switch in RUN or START, voltage is supplied through the GAGES fuse through PNK/BLK (39) wire to the Audio Alarm Module. With the driver's safety belt not buckled, the BLK (238) wire sends a ground signal to the module. The ground signal on the BLK (238) wire is also sent to the Diagnostic Energy Reserve module of the AIR BAG system. The Fasten Belts Indicator always goes on for about five seconds when the Ignition Switch is turned to RUN or START. Lights-On Warning (Chime Only) When the Light Switch is in HEAD or PARK and the Panel Dimmer Switch is not at the dimmest setting, voltage is supplied through the INSTR LPS Fuse to the Audio Alarm Module. With the Panel Dimmer Switch at its dimmest setting, the current to the Audio Alarm may not be enough to be sensed by the module. When the Ignition Switch is turned to RUN or START, voltage is supplied through the GAGES Fuse and the PNK/BLK (39) wire to the Module. These two voltages are sensed and the alarm is not sounded. When the Ignition Switch is turned to LOCK, OFF, or ACC, the GAGES Fuse loses voltage. The Audio Alarm Module senses the change. If voltage is still available from the INSTR LPS Fuse, voltage from the STOP-HZ Fuse is supplied to sound the alarm. The alarm can be turned off by turning the Light Switch off. The Module no longer senses voltage from the Light Switch, so the alarm does not sound. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions Audible Warning Device Control Module: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7856 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7857 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7858 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7859 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7860 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7861 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7862 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7863 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7864 Audible Warning Device Control Module: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7865 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7866 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7867 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7868 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7869 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7870 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7871 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7872 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7873 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7874 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7875 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7876 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7877 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7878 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7879 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7880 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7881 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7882 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7883 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7884 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7885 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7886 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 7887 Audio Alarm Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions Brake Warning Indicator: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7892 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7893 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7894 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7895 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7896 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7897 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7898 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7899 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7900 Brake Warning Indicator: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7901 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7902 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7903 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7904 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7905 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7906 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7907 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7908 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7909 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7910 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7911 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7912 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7913 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7914 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7915 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7916 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7917 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7918 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7919 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7920 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7921 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7922 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7923 Brake Warning Indicator: Electrical Diagrams Brake Warning System Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 7924 Brake Warning System Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Diagrams > Page 7925 Brake Warning Indicator: Description and Operation Battery voltage is supplied to the Brake Indicator through the GAGES Fuse and the PNK/BLK (39) wire when the Ignition Switch is in RUN or START. Ground is provided through the TAN/WHT (33) wire by the Park Brake Warning Switch, Brake Pressure Warning Lamp Switch or the Electronic Hydraulic Control Unit (EHCU) also called Antilock Electronic Brake Control Module. The Park Brake Warning Switch closes when the Parking Brake is applied. The Brake Indicator lights to alert the driver. The Brake Pressure Warning Lamp Switch closes to light the Brake Indicator when there is low brake fluid pressure in one of the two hydraulic brake systems. This could be caused by a leak in one of the brake lines. Refer to Switch reset procedure. This can only be accomplished after the system has been repaired. The Four-Wheel Antilock Brake Module grounds the Brake Indicator when the module senses certain malfunctions in the hydraulic portion of the system. The Four-Wheel Antilock Brake Module grounds the Antilock Indicator when the module senses a malfunction in the electrical or electronic portion of the system. Brake voltage input is supplied to the Module through the Stoplamp Switch whenever the brakes are applied. For the Four-Wheel Antilock Brake System Description and Diagnosis refer to Antilock Brake System See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Brake Warning Indicator: Initial Inspection and Diagnostic Overview Preliminary Checks 1. Check condition of BRAKE fuse. If fuse is blown, locate and repair source of overload. replace fuse. 2. Refer to Brakes for the diagnostic circuit check and diagnostic trouble code identification. 3. Check to see that the BLK (2) fusible link is not burned out. replace if burned out. Circuit Operation Battery voltage is supplied to the Brake Indicator through the GAGES Fuse and the PNK/BLK (39) wire when the Ignition Switch is in RUN or START. Ground is provided through the TAN/WHT (33) wire by the Park Brake Warning Switch, Brake Pressure Warning Lamp Switch or the Electronic Hydraulic Control Unit (EHCU) also called Antilock Electronic Brake Control Module. The Park Brake Warning Switch closes when the Parking Brake is applied. The Brake Indicator lights to alert the driver. The Brake Pressure Warning Lamp Switch closes to light the Brake Indicator when there is low brake fluid pressure in one of the two hydraulic brake systems. This could be caused by a leak in one of the brake lines. Refer to Switch reset procedure. This can only be accomplished after the system has been repaired. The Four-Wheel Antilock Brake Module grounds the Brake Indicator when the module senses certain malfunctions in the hydraulic portion of the system. The Four-Wheel Antilock Brake Module grounds the Antilock Indicator when the module senses a malfunction in the electrical or electronic portion of the system. Brake voltage input is supplied to the Module through the Stoplamp Switch whenever the brakes are applied. For the Four-Wheel Antilock Brake System Description and Diagnosis refer to Antilock Brake System See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 7928 Brake Warning Indicator: Symptom Related Diagnostic Procedures Brake Indicator Does Not Light During A Warning Condition Or During The Antilock System Check Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Brake Warning Indicator > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 7929 Brake Indicator Remains ON With Ignition Switch In Run And Park Brake Off (Part 1 Of 2) Brake Indicator Remains ON With Ignition Switch In Run And Park Brake OFF (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Charge Lamp/Indicator > Component Information > Testing and Inspection Charge Lamp/Indicator: Testing and Inspection Before performing diagnostic procedures, ensure system wiring is good, alternator belt is tight, and battery is fully charged. TROUBLESHOOTING 1. Check drive belt for wear and proper adjustment. 2. With ignition switch on and engine off, charging indicator lamp should be on. Fig. 23 Charge Indicator Lamp Wiring System. Delcotron Charging System. 3. If indicator lamp is not on, disconnect wiring harness at alternator. Ground "L terminal using a fused 5 amp jumper wire. 4. If lamp lights, replace alternator. If lamp does not light, check for a open between the grounding lead and the ignition switch. Reconnect wiring. 5. With switch on and engine running at a moderate RPM, lamp should be off. If not, stop engine, turn switch on, then disconnect wiring harness at alternator. 6. If lamp goes out, replace alternator. 7. If lamp stays on, check for a grounded "L terminal wire in harness. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Cigarette Lighter > Component Information > Locations Cigarette Lighter: Locations Cigarette Lighter And Courtesy Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Cigarette Lighter > Component Information > Locations > Page 7936 Cigarette Lighter And Courtesy Lamp (W/Auxiliary Lighting Package) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Cigarette Lighter > Component Information > Locations > Page 7937 C229, Cigarette Lighter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 7943 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Dash Board / Instrument Panel <--> [Dashboard / Instrument Panel] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Dash Board / Instrument Panel <--> [Dashboard / Instrument Panel] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 7949 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Restraint Systems/Air Bag Systems/Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Dash Board / Instrument Panel <--> [Dashboard / Instrument Panel] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 7950 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Dimmer Switch > Component Information > Technical Service Bulletins > IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Dimmer Switch > Component Information > Technical Service Bulletins > Page 7955 Dimmer Switch: Locations Instrument Panel, LH Side Headlights Switch Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Dimmer Switch > Component Information > Technical Service Bulletins > Page 7956 Dimmer Switch: Diagrams C299, Resistance Wire To Panel Dimmer Switch C299, Panel Dimmer Switch To Resistance Wire C218, Panel Dimmer Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Door Switch > Component Information > Locations > Door Jamb Switch, LH Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 7961 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 7962 RH I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 7963 Door Switch: Locations Door Jamb Switch, Sliding Side Side Door Switches And Wiring In RH B-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Door Switch > Component Information > Locations > Page 7964 C325, LH Door Jamb Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Fuel Gauge > Component Information > Testing and Inspection > Fuel Gauge Inaccurate Fuel Gauge: Testing and Inspection Fuel Gauge Inaccurate 1. Ensure terminals are clean and terminal connections are tight. 2. Disconnect fuel tank sender connector, then connect tester J 33431-B, or equivalent, as follows: - Connect tester red lead to purple wire of the connector, then connect the other lead of the tester to a suitable ground. 3. Set resistance dials of tester to 0 ohms and then to 90 ohms. 4. Gauge should read low when resistance is set to 0 ohms and read full when resistance is set to 90 ohms. Allow some time for gauge to read full due to the anti-slosh device. 5. If gauge responds accurately, check for clean mounting surface on sending unit to ensure a good ground. If ground is good, replace sending unit. 6. If gauge does not respond accurately, check circuit between gauge and sending unit for an open or short to ground. If circuit is satisfactory, replace gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Fuel Gauge > Component Information > Testing and Inspection > Fuel Gauge Inaccurate > Page 7969 Fuel Gauge: Testing and Inspection Gauge Stays at Empty This condition is generally caused by a short in the fuel tank wiring circuit. 1. Ensure fuel tank is full, then disconnect lead at fuel tank and turn ignition switch to the On position. 2. If gauge moves but not past full mark, replace fuel tank sending unit. 3. If gauge stays at empty, locate and repair short in circuit between gauge and fuel tank. If circuit is satisfactory, replace gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Fuel Gauge > Component Information > Testing and Inspection > Fuel Gauge Inaccurate > Page 7970 Fuel Gauge: Testing and Inspection Gauge Stays at Full or Beyond This condition is generally caused by a open circuit between the gauge and sending unit. 1. Disconnect sender lead at fuel tank, then ground lead and turn ignition switch to the On position. 2. If fuel gauge reads empty, replace tank sending unit. 3. If gauge reads at full or beyond, locate and repair open in circuit between gauge and fuel tank. If circuit is satisfactory, replace gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Fuel Gauge Sender > Component Information > Locations Fuel Pump And Sender Assembly (Typical) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Fuel Gauge Sender > Component Information > Locations > Page 7974 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull fuel pump up into attaching hose while pulling outward from the bottom support. ^ Do not damage rubber insulator or strainer. INSPECTION: 1. Inspect fuel pump attaching hose for signs of deterioration. 2. Inspect rubber sound insulation at bottom of pump for deterioration. INSTALLATION: 1. Install pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). 3. Install cam lock assembly. Turn cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect negative battery cable. 6. START vehicle and check for fuel leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Instrument Cluster / Carrier <--> [Instrument Cluster / Carrier] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming Air Bag(s) Arming and Disarming: Service and Repair Air Bag Disarming and Arming Disabling the SIR System REMOVE OR DISCONNECT ^ Turn the steering wheel so that the vehicle's wheels are pointing straight ahead. ^ Turn the ignition switch to "LOCK" and remove key. 1. "AIR BAG" fuse from fuse block. 2. Steering column filler panel. 3. Connector Position Assurance (CPA) and yellow 2-way connector at the base of the steering column. IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. Enabling the SIR System IMPORTANT ^ With the "AIR BAG" fuse removed and ignition switch "ON," the "AIR BAG" warning lamp will be "ON." This is normal operation and does not indicate an SIR system malfunction. INSTALL OR CONNECT ^ Turn ignition switch to "LOCK" and remove key. 1. Yellow 2-way connector at the base of the steering column and Connector Position Assurance (CPA). 2. Steering column filler panel. 3. "AIR BAG" fuse to fuse block. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Instrument Cluster / Carrier <--> [Instrument Cluster / Carrier] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 7980 ^ Turn ignition switch to "RUN" and verify that the "AIR BAG" warning lamp flashes seven times and then turns "OFF." If it does not operate as described, perform the "SIR Diagnostic System Check." See: Restraint Systems/Air Bag Systems/Testing and Inspection Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Instrument Cluster / Carrier <--> [Instrument Cluster / Carrier] > Air Bag(s) Arming and Disarming > System Information > Service and Repair > Air Bag Disarming and Arming > Page 7981 Air Bag(s) Arming and Disarming: Service and Repair General Service Precautions CAUTION: When performing service on or around SIR components or SIR wiring, follow the procedures listed to temporarily disable the SIR system. Failure to follow procedures could result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Malfunction Indicator Lamp > Component Information > Service and Repair Malfunction Indicator Lamp: Service and Repair The CHECK ENGINE LAMP will be illuminated when the ignition switch is placed in the "ON" position. When the engine is started, the lamp should turn "OFF". If the lamp remains "ON" for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Control Module. After diagnosis and repair, the ECM memory can be cleared of codes by removing the Control Module fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the "OFF" position. NOTE If battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. - It is a good idea to record preset radio stations before disconnecting the negative battery cable. This will allow the stations to be reset as to not inconvenience the customer. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Odometer > Component Information > Technical Service Bulletins > Odometer/Speedometer - ACDelco Service Center Locations Odometer: Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Odometer > Component Information > Technical Service Bulletins > Odometer/Speedometer - ACDelco Service Center Locations > Page 7989 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Odometer > Component Information > Technical Service Bulletins > Odometer/Speedometer - ACDelco Service Center Locations > Page 7990 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Odometer > Component Information > Technical Service Bulletins > Odometer/Speedometer - ACDelco Service Center Locations > Page 7991 AC Delco Service Centers Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Gauge > Component Information > Locations Oil Pressure Gauge: Locations Coolant Temperature And Oil Pressure Sensor Locations Located on the top left side of the engine, near the distributor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate Oil Pressure Gauge: Testing and Inspection Gauge Readings Are Inaccurate 1. Remove lead from sensor, then connect tester J 33431-A or equivalent to sensor lead and ground. 2. If gauge responds accurately to tester, replace sensor. 3. If gauge does not respond accurately to tester, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 7997 Oil Pressure Gauge: Testing and Inspection Gauge Reads High 1. Disconnect lead from sensor, then turn ignition switch to the ON position and ground lead. 2. If gauge reads low, replace sensor. 3. If gauge reads high, locate and repair open circuit between sensor and gauge. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 7998 Oil Pressure Gauge: Testing and Inspection Gauge Reads Low 1. Check oil level, add if necessary. 2. Turn ignition switch to the On position. 3. Remove oil pressure sensor lead at sensor, gauge should read high. 4. If gauge stays low, remove sensor lead at gauge. Gauge should read high. If gauge reads high, locate and repair short to ground between gauge and sensor. 5. If gauge still reads low, replace cluster. 6. With lead removed at sensor, connect an ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 7. If sensor reads significantly lower than 44 ohms with engine running, replace sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks use a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit--which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation > Page 8015 Oil Pressure Warning Lamp/Indicator: Testing and Inspection The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations Fuse Block And Rear Body Harness Fuse Block And Rear Body Harness Below LH side of I/P, on park brake lower assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch C255, Park Brake Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch > Page 8021 Parking Brake Warning Switch: Diagrams Park Brake Warning Switch In-Line C225, Park Brake Warning Switch In-line C225, Park Brake Warning Switch In-line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions Audible Warning Device Control Module: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8027 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8028 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8029 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8030 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8031 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8032 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8033 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8034 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8035 Audible Warning Device Control Module: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8036 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8037 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8038 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8039 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8040 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8041 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8042 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8043 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8044 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8045 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8046 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8047 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8048 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8049 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8050 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8051 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8052 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8053 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8054 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8055 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8056 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8057 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Relays and Modules - Instrument Panel > Audible Warning Device Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 8058 Audio Alarm Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 8064 Dimmer Switch: Locations Instrument Panel, LH Side Headlights Switch Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 8065 Dimmer Switch: Diagrams C299, Resistance Wire To Panel Dimmer Switch C299, Panel Dimmer Switch To Resistance Wire C218, Panel Dimmer Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8070 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8071 RH I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8072 Door Switch: Locations Door Jamb Switch, Sliding Side Side Door Switches And Wiring In RH B-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Page 8073 C325, LH Door Jamb Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations Fuel Pump And Sender Assembly (Typical) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations > Page 8077 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull fuel pump up into attaching hose while pulling outward from the bottom support. ^ Do not damage rubber insulator or strainer. INSPECTION: 1. Inspect fuel pump attaching hose for signs of deterioration. 2. Inspect rubber sound insulation at bottom of pump for deterioration. INSTALLATION: 1. Install pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). 3. Install cam lock assembly. Turn cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect negative battery cable. 6. START vehicle and check for fuel leaks. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations Fuse Block And Rear Body Harness Fuse Block And Rear Body Harness Below LH side of I/P, on park brake lower assembly Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch C255, Park Brake Warning Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Diagrams > C255, Park Brake Warning Switch > Page 8083 Parking Brake Warning Switch: Diagrams Park Brake Warning Switch In-Line C225, Park Brake Warning Switch In-line C225, Park Brake Warning Switch In-line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > Customer Interest: > 468203A > Jun > 95 > Inoperative, Erratic Speedometer/Shifting/DTCs Set Speedometer Head: Customer Interest Inoperative, Erratic Speedometer/Shifting/DTCs Set FILE IN SECTION: 8 - Chassis/Body Electrical BULLETIN NO.: 46-82-03A DATE: June, 1995 SUBJECT: Inoperative or Erratic Speedometer and/or Vehicle Shifts Down Into Second Gear or Will Not Shift Out of Second Gear (Replace Connector C24O) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans with 4L6OE Transmission (RPO M30) This bulletin being revised to correct the parts information. Please Discard Corporate Bulletin Number 46-82-03 (Section 8 - Chassis/Body Electrical). CONDITION Some owners may experience: inoperative or erratic speedometer, which could result in setting a Diagnostic Trouble Code 24 or 72; the vehicle shifting down into second gear, which may set a Diagnostic Trouble Code 24; or the vehicle will not shift out of second gear, which could result in a Diagnostic Trouble Code 72. CAUSE Moisture in the instrument panel harness C240 connector. CORRECTION This connector is located on the passenger side kick panel (Figure 1). Determine source of moisture and install proper seal to prevent recurrence of moisture intrusion. Replace C240 connector with connectors (P/N 12167122 and 12125675) and terminals (P/N 12045773). Use silicone grease on terminals to prevent corrosion. Proper procedures for replacement of connectors and terminals will be found in M/L Service Manual # NATP-9443, Section 8A-2. Be certain to label wires prior to replacing connectors, to assure proper location in new connectors. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > Customer Interest: > 468203A > Jun > 95 > Inoperative, Erratic Speedometer/Shifting/DTCs Set > Page 8092 PARTS INFORMATION P/N Description Qty 12167122 Connector 1 12125675 Connector 1 12045773 Terminal (Package of 10) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time N6360 I/P Wiring Use Published and/or Connector - Labor Operation Repair. Time N6270 Engine Wiring Use Published and/or Connector - Labor Operation Repair Time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: All Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 8098 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 8099 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 8100 AC Delco Service Centers Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Speedometer Head: > 468203A > Jun > 95 > Inoperative, Erratic Speedometer/Shifting/DTCs Set Speedometer Head: All Technical Service Bulletins Inoperative, Erratic Speedometer/Shifting/DTCs Set FILE IN SECTION: 8 - Chassis/Body Electrical BULLETIN NO.: 46-82-03A DATE: June, 1995 SUBJECT: Inoperative or Erratic Speedometer and/or Vehicle Shifts Down Into Second Gear or Will Not Shift Out of Second Gear (Replace Connector C24O) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans with 4L6OE Transmission (RPO M30) This bulletin being revised to correct the parts information. Please Discard Corporate Bulletin Number 46-82-03 (Section 8 - Chassis/Body Electrical). CONDITION Some owners may experience: inoperative or erratic speedometer, which could result in setting a Diagnostic Trouble Code 24 or 72; the vehicle shifting down into second gear, which may set a Diagnostic Trouble Code 24; or the vehicle will not shift out of second gear, which could result in a Diagnostic Trouble Code 72. CAUSE Moisture in the instrument panel harness C240 connector. CORRECTION This connector is located on the passenger side kick panel (Figure 1). Determine source of moisture and install proper seal to prevent recurrence of moisture intrusion. Replace C240 connector with connectors (P/N 12167122 and 12125675) and terminals (P/N 12045773). Use silicone grease on terminals to prevent corrosion. Proper procedures for replacement of connectors and terminals will be found in M/L Service Manual # NATP-9443, Section 8A-2. Be certain to label wires prior to replacing connectors, to assure proper location in new connectors. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Speedometer Head: > 468203A > Jun > 95 > Inoperative, Erratic Speedometer/Shifting/DTCs Set > Page 8105 PARTS INFORMATION P/N Description Qty 12167122 Connector 1 12125675 Connector 1 12045773 Terminal (Package of 10) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time N6360 I/P Wiring Use Published and/or Connector - Labor Operation Repair. Time N6270 Engine Wiring Use Published and/or Connector - Labor Operation Repair Time. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Other Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: All Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Other Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 8111 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Other Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 8112 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Speedometer Head > Component Information > Technical Service Bulletins > All Other Service Bulletins for Speedometer Head: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 8113 AC Delco Service Centers Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot Temperature Gauge: Testing and Inspection Gauge Does Not Move From Cold When Engine Is Hot This condition is generally caused by a blown fuse, open circuit or faulty sensor. 1. Check fuse, replace if necessary. 2. Turn ignition switch to On position, then remove lead at sensor unit. 3. Connect test lamp from sensor lead to ground, lamp should glow. Short sensor lead to ground, gauge should indicate "Hot." 4. If gauge indicated HOT, check lead on sensor. If satisfactory, replace sensor. If gauge indicates COLD, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 8118 Temperature Gauge: Testing and Inspection Gauge Indicates Hot When Engine Is Cold This condition is generally caused by a shorted or grounded circuit. 1. Remove sensor lead at sensor unit. Gauge should move to COLD position, if not check unit for a external short. If no external short is found, replace sensor. 2. If gauge stays HOT, check for a short circuit in gauge to sensor wiring. If circuit is satisfactory, replace cluster. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 8119 Temperature Gauge: Testing and Inspection Gauge Reads High 1. Remove lead at sensor, measure resistance using an ohmmeter. 2. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 3. If resistance is not within specifications, replace sensor. 4. Disconnect lead at sensor and gauge, check for a high resistance using an ohmmeter. Repair wiring if necessary. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 8120 Temperature Gauge: Testing and Inspection Gauge Reads Low 1. Ensure terminals are clean and connections are tight. 2. Remove lead at sensor, measure resistance using an ohmmeter. 3. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 4. If resistance is not within specifications, replace sensor. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor Temperature Sensor (Gauge): Locations Engine Coolant Temperature (ECT) Gage Sensor Engine Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 8125 Engine Wiring, Rear - 4.3L High Performance Engine (Vin W) Others Similar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Sensor (Gauge) > Component Information > Locations > Engine Coolant Temperature (ECT) Gage Sensor > Page 8126 Engine Wiring, Rear Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation Temperature Warning Lamp/Indicator: Description and Operation A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation > Page 8130 Temperature Warning Lamp/Indicator: Testing and Inspection If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Transmission Shift Position Indicator Lamp > Component Information > Technical Service Bulletins > Instruments - Reduced PRNDL Display Visibility Transmission Shift Position Indicator Lamp: Technical Service Bulletins Instruments - Reduced PRNDL Display Visibility Bulletin No.: 02-08-42-004A Date: March 30, 2007 INFORMATION Subject: PRNDL Display Reduced Visibility For Approximately One Minute Models: 2007 and Prior Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Automatic Headlamp Control and Vacuum Fluorescent PRNDL Indicator Instrument Panel Cluster Supercede: This bulletin is being revised to include additional models and model years. Please discard Corporate Bulletin Number 02-08-42-0004 (Section 08 - Body and Accessories). After backing the vehicle out of a garage or dark environment into a daylight environment, the PRNDL display has reduced visibility for approximately one minute. While the vehicle is parked in a dark environment, the sensor for the automatic headlamp/driving lamps senses that it is dark. When the key is turned to the run/start position, the automatic headlamp module will turn all driving lamps, the instrument panel cluster and PRNDL display ON in the night-time mode. The night-time mode intensity of the instrument panel lamps and PRNDL display is controlled by the automatic headlamp module and can be dimmed further by the customer using the dimming control of the headlamp switch. When the customer then moves the vehicle from the dark environment into the bright sunlight, it will take approximately one minute before the headlamp control module recognizes this as true daylight and not just a bright overhead street lamp shining on the sensor. The headlamp control module will then turn the headlamps off and restore the instrument panel and PRNDL display to full brilliance. Without the time delay, the automatic headlamp control module would switch to the night mode (turn on all driving lamps, instrument panel lamps and PRNDL display would dim) each time the vehicle was driven under an overpass or other darkened environment. This is a normal condition and no repair should be attempted. Ensure the instrument panel backlighting control is in the full bright position. This will help alleviate the condition. You may demonstrate to the customer what happens by placing a repair order over the automatic headlamp control light sensor, which will cause the automatic headlamp control module to switch to the night mode in approximately one minute. All driving lamps will come ON, the instrument panel backlight will be dim, and the PRNDL display will also dim to the night setting in conjunction with the position of the headlamp switch dimming control. Demonstrate to the customer the variance in the instrument panel backlighting and PRNDL display while adjusting the headlamp switch dimming control to both ends of its allowable range. Advise the customer to keep the headlight switch dimming control in the highest position to allow viewing of the PRNDL display in a bright environment. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Transmission Shift Position Indicator Lamp > Component Information > Locations > Transmission Range Indicator Lamp Instrument Panel Cluster Wiring (W/Electronic Cluster) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Transmission Shift Position Indicator Lamp > Component Information > Locations > Transmission Range Indicator Lamp > Page 8137 Transmission Shift Position Indicator Lamp: Locations Transmission Range Indicator Lamp Relay Instrument Panel Cluster Wiring (W/Electronic Cluster) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Transmission Shift Position Indicator Lamp > Component Information > Locations > Transmission Range Indicator Lamp > Page 8138 Instrument Panel Cluster Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Transmission Shift Position Indicator Lamp > Component Information > Locations > Page 8139 C202A, Transmission Range Indicator Lamp Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Vacuum Gauge/Economy Meter > Component Information > Description and Operation Vacuum Gauge/Economy Meter: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except the switch opens when vacuum pressure, rather than oil pressure, is applied. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Vacuum Gauge/Economy Meter > Component Information > Description and Operation > Page 8143 Vacuum Gauge/Economy Meter: Testing and Inspection The fuel economy warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the fuel economy vacuum switch connector and ground the wire to the frame or cylinder block. If the warning light still does not go on, check for burned out indicating bulb or an open in the harness between the vacuum switch and instrument panel. If the warning light goes on, circuit is functioning and the vacuum switch should be checked for proper ground. Remove and clean the mounting bracket screws and the mounting surfaces. If the warning light remains lit when it normally should be out, check vacuum hose to vacuum switch for damage or plugged condition. If system still does not operate correctly, perform the following steps: 1. Disconnect electrical connector and vacuum tube from switch. 2. Connect a self-powered test light to the switch electrical connector and to the vacuum gauge mounting bracket. 3. With vacuum applied, test light should be off. 4. With no vacuum to the vacuum switch, test light should be on. 5. Replace switch if test light did not function as specified. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Instrument Panel, Gauges and Warning Indicators > Volt Meter Gauge > Component Information > Testing and Inspection Volt Meter Gauge: Testing and Inspection To check voltmeter, turn ignition switch and headlights on with engine off. Pointer should move to 12.5 volts. If no needle movement is observed, check connections from battery to circuit breaker. If connections are tight and clean, check wire continuity. If wire continuity is satisfactory, replace the voltmeter. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Backup Lamp > Backup Lamp Switch > Component Information > Locations Backup Lamp Switch: Locations Instrument Panel, LH Side On steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Backup Lamp > Backup Lamp Switch > Component Information > Locations > Page 8152 C217, Backup Lamp Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement Brake Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement > Page 8157 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Lamp > Component Information > Technical Service Bulletins > Page 8158 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Lamp > Component Information > Diagrams > LH C400, LH Tail, Stop And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Lamp > Component Information > Diagrams > LH > Page 8161 C401, RH Tail, Stop And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions Brake Light Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8167 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8168 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8169 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8170 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8171 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8172 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8173 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8174 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8175 Brake Light Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8176 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8177 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8178 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8179 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8180 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8181 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8182 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8183 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8184 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8185 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8186 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8187 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8188 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8189 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8190 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8191 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8192 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8193 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8194 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8195 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8196 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8197 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8198 Brake Light Switch: Connector Views C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8199 Brake Light Switch: Electrical Diagrams PCM Wiring Diagram (3 Of 5) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8200 Exterior Lamps (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8201 Exterior Lamps (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8202 Exterior Lamps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8203 Brake/Transmission Shift Interlock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8204 Cruise Control Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Page 8205 Brake Light Switch: Service and Repair Fig. 15 Stop Lamp Switch Replacement. The zero adjust stop lamp switch does not need adjustment because the switch is installed along with the brake push rod and held by a single retainer. 1. Disconnect battery ground cable. 2. Disconnect stop lamp switch electrical connector. 3. Disconnect retainer from brake pedal pin, Fig. 15. 4. Remove stop lamp switch by unsnapping from pushrod. 5. To install switch, snap into pushrod. 6. Snap retainer onto brake pedal pin, then connect switch electrical connector. 7. Connect battery ground cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Center Mounted Brake Lamp > Component Information > Locations Center High Mounted Stoplamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Courtesy Lamp > Ash Tray Lamp > Component Information > Locations Ash Tray Lamp: Locations Cigarette Lighter And Courtesy Lamp (W/Auxiliary Lighting Package) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Courtesy Lamp > Ash Tray Lamp > Component Information > Locations > Page 8213 Cigarette Lighter And Courtesy Lamp (W/Auxiliary Lighting Package) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Courtesy Lamp > Ash Tray Lamp > Component Information > Locations > Page 8214 Ash Tray Lamp: Diagrams C228, Ashtray Lamp Socket C203A, Ashtray Lamp C228, Ashtray Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Courtesy Lamp > Glove Box Lamp > Component Information > Diagrams C227, I/P Compartment Box Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Daytime Running Lamp > Daytime Running Lamp Control Unit > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Daytime Running Lamp > Daytime Running Lamp Control Unit > Component Information > Locations > Page 8222 C260, DRL Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Daytime Running Lamp > Daytime Running Lamp Relay > Component Information > Locations Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Daytime Running Lamp > Daytime Running Lamp Relay > Component Information > Locations > Page 8226 C144, DRL Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dimmer Switch > Component Information > Technical Service Bulletins > IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dimmer Switch > Component Information > Technical Service Bulletins > Page 8231 Dimmer Switch: Locations Instrument Panel, LH Side Headlights Switch Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dimmer Switch > Component Information > Technical Service Bulletins > Page 8232 Dimmer Switch: Diagrams C299, Resistance Wire To Panel Dimmer Switch C299, Panel Dimmer Switch To Resistance Wire C218, Panel Dimmer Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dome Lamp > Component Information > Locations > Dome Lamp Switch Dome Lamp: Locations Dome Lamp Switch Courtesy Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dome Lamp > Component Information > Locations > Dome Lamp Switch > Page 8237 Courtesy Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dome Lamp > Component Information > Locations > Dome Lamp Switch > Page 8238 Dome Lamp: Locations Dome Light, Front Reading And Rear Dome Lamps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dome Lamp > Component Information > Locations > Dome Lamp Switch > Page 8239 Front Dome And Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dome Lamp > Component Information > Locations > Dome Lamp Switch > Page 8240 Reading And Rear Dome Lamps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Dome Lamp > Component Information > Locations > Page 8241 C219, Dome Lamp Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8246 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8247 RH I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8248 Door Switch: Locations Door Jamb Switch, Sliding Side Side Door Switches And Wiring In RH B-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Door Switch > Component Information > Locations > Page 8249 C325, LH Door Jamb Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location Exterior Lighting Module: Technical Service Bulletins Exterior Lights - Revised Schematic, Component Location File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-81-07 Date: September, 1996 SERVICE MANUAL UPDATE Subject: Section 8A-110 - Exterior Lights - Revised Text Pages and Art Pages Models: 1994 Chevrolet and GMC M/L Models Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8254 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8255 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8256 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8257 This bulletin revises the System Schematic, Component Location Index, Connector End View and Component Location View for the Exterior Lights System in Section 8A-110. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Fog/Driving Lamp > Fog/Driving Lamp Relay > Component Information > Locations Fog/Driving Lamp Relay: Locations Instrument Panel Fog Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Fog/Driving Lamp > Fog/Driving Lamp Relay > Component Information > Locations > Page 8262 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Fog/Driving Lamp > Fog/Driving Lamp Switch > Component Information > Locations Fog/Driving Lamp Switch: Locations Instrument Panel Fog Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Fog/Driving Lamp > Fog/Driving Lamp Switch > Component Information > Locations > Page 8266 Radio, Clock And Memory Feed Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Dimmer Switch > Component Information > Locations Headlamp Dimmer Switch: Locations Instrument Panel, LH Side On LH side of steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Dimmer Switch > Component Information > Locations > Page 8271 Headlamp Dimmer Switch: Service and Repair Fig. 19 Ignition Lock & Dimmer Switch Replacement. 1. Disconnect battery ground cable. 2. Remove lower steering column cover. 3. Remove washer head screw (54) and hexagon washer head tapping screw (69), Fig. 19. 4. Remove dimmer switch assembly, Fig. 19. 5. Remove flat head screw (67), then the ignition switch assembly with switch actuator rod, Fig. 19. 6. Remove switch actuating rod from ignition switch. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Lens > Component Information > Technical Service Bulletins > Lighting - Headlamp Polycarbonate Lens Damage Prevention Headlamp Lens: Technical Service Bulletins Lighting - Headlamp Polycarbonate Lens Damage Prevention INFORMATION Bulletin No.: 02-08-42-001D Date: June 21, 2010 Subject: Headlamp Lens Overheating When Covered and Chemical Damage to Exterior Polycarbonate Headlamp Lenses Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and to revise the warning statements. Please discard Corporate Bulletin Number 02-08-42-001C (Section 08 - Body and Accessories). The bulletin is being issued to make dealers and customers aware of chemical damage that may be caused to exterior polycarbonate headlamp lenses. Most late model vehicles have these types of headlamp lenses. This material is used because of its temperature and high impact resistance. A variety of chemicals can cause crazing or cracking of the headlamp lens. Headlamp lenses are very sensitive. Care should be exercised to avoid contact with all exterior headlamp lenses when treating a vehicle with any type of chemical, such as those recommended for rail dust removal. Rubbing compound, grease tar and oil removers, tire cleaners, cleaner waxes and even car wash soaps in too high a concentration may also attribute to this condition. This could result in the need to replace the entire headlamp housing. Warning Use only lukewarm or cold water, a soft cloth and a car washing soap to clean exterior lamps and lenses. Also, crazing or deformations of the lens may occur if a shop mat or fender cover is draped over the fender and covers a portion or all of the headlamp assembly while the DRL or headlamps are on. This action restricts the amount of heat dissipated by the headlamps. Warning Care should be taken to not cover headlamps with shop mats or fender covers if the vehicle is being serviced with the headlamps or DRL illuminated. Covering an illuminated lamp can cause excessive heat build up and crazing/deformation of the lens may occur. The degradation of the lens can be unnoticeable at first and eventually become hairline cracks in the lens. In extreme cases, it could cause the lens to deform. This damage can also be caused by aftermarket shields that are often tinted in color. Once a heat buildup is generated by the headlamp, a degradation of the headlamp lens begins. This degradation of the lens can be unnoticeable at first and eventually manifest as spider cracks. In more extreme cases, it will begin to melt the lens of the headlamp. Notice Headlamps damaged by chemicals, improper cleaning, or overheating due to being covered are not covered under the new vehicle warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Locations Headlamp Switch: Locations Headlights Switch Wiring Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Locations > Page 8279 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions Headlamp Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8282 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8283 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8284 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8285 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8286 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8287 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8288 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8289 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8290 Headlamp Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8291 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8292 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8293 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8294 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8295 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8296 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8297 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8298 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8299 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8300 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8301 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8302 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8303 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8304 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8305 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8306 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8307 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8308 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8309 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8310 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8311 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8312 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8313 C202, Headlight Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8314 Headlamp Switch: Electrical Diagrams Light Switch Details (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8315 Light Switch Details (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Page 8316 Headlamp Switch: Description and Operation HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Headlamp circuit draws too much current. When the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off and resets automatically. When the Light Switch is in HEAD, the Headlamp Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beam Indicator also receives voltage along with the High Beams. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Headlamp > Headlamp Switch > Component Information > Diagrams > Page 8317 Headlamp Switch: Testing and Inspection HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Headlamp circuit draws too much current. When the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off and resets automatically. When the Light Switch is in HEAD, the Headlamp Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beam Indicator also receives voltage along with the High Beams. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Hi-Beam Indicator Lamp > Component Information > Locations Hi-Beam Indicator Lamp: Locations In instrument cluster Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Horn > Horn Relay > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Horn > Horn Switch > Component Information > Locations Horn Switch: Locations In steering wheel Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > License Plate Lamp > Component Information > Locations Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > License Plate Lamp > Component Information > Locations > Page 8331 C904, License Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Map Light > Component Information > Locations Reading And Rear Dome Lamps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Marker Lamp > Component Information > Locations Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Marker Lamp > Component Information > Locations > Page 8338 Marker Lamp: Diagrams C403, RH Side Marker Lamp C131, LH Side Marker Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Parking Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement Parking Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Parking Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement > Page 8343 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Parking Lamp > Component Information > Technical Service Bulletins > Page 8344 Parking Lamp: Locations LH rear of vehicle Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Parking Lamp > Component Information > Technical Service Bulletins > Page 8345 Parking Lamp: Diagrams C136, RH Park And Turn Lamp C135, LH Park And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Daytime Running Lamp Control Unit > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Daytime Running Lamp Control Unit > Component Information > Locations > Page 8350 C260, DRL Module Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Daytime Running Lamp Relay > Component Information > Locations Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Daytime Running Lamp Relay > Component Information > Locations > Page 8354 C144, DRL Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location Exterior Lighting Module: Technical Service Bulletins Exterior Lights - Revised Schematic, Component Location File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-81-07 Date: September, 1996 SERVICE MANUAL UPDATE Subject: Section 8A-110 - Exterior Lights - Revised Text Pages and Art Pages Models: 1994 Chevrolet and GMC M/L Models Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8359 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8360 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8361 Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Exterior Lighting Module > Component Information > Technical Service Bulletins > Exterior Lights - Revised Schematic, Component Location > Page 8362 This bulletin revises the System Schematic, Component Location Index, Connector End View and Component Location View for the Exterior Lights System in Section 8A-110. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Fog/Driving Lamp Relay > Component Information > Locations Fog/Driving Lamp Relay: Locations Instrument Panel Fog Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Fog/Driving Lamp Relay > Component Information > Locations > Page 8366 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Relays and Modules - Lighting and Horns > Horn Relay > Component Information > Locations Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Backup Lamp Switch > Component Information > Locations Backup Lamp Switch: Locations Instrument Panel, LH Side On steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Backup Lamp Switch > Component Information > Locations > Page 8374 C217, Backup Lamp Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Locations Cruise Control Module And Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions Brake Light Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8380 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8381 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8382 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8383 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8384 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8385 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8386 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8387 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8388 Brake Light Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8389 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8390 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8391 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8392 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8393 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8394 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8395 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8396 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8397 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8398 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8399 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8400 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8401 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8402 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8403 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8404 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8405 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8406 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8407 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8408 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8409 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8410 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8411 Brake Light Switch: Connector Views C251, Brake Switch C215, Brake Switch C233, TCC/Brake Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8412 Brake Light Switch: Electrical Diagrams PCM Wiring Diagram (3 Of 5) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8413 Exterior Lamps (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8414 Exterior Lamps (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8415 Exterior Lamps Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8416 Brake/Transmission Shift Interlock Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8417 Cruise Control Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Page 8418 Brake Light Switch: Service and Repair Fig. 15 Stop Lamp Switch Replacement. The zero adjust stop lamp switch does not need adjustment because the switch is installed along with the brake push rod and held by a single retainer. 1. Disconnect battery ground cable. 2. Disconnect stop lamp switch electrical connector. 3. Disconnect retainer from brake pedal pin, Fig. 15. 4. Remove stop lamp switch by unsnapping from pushrod. 5. To install switch, snap into pushrod. 6. Snap retainer onto brake pedal pin, then connect switch electrical connector. 7. Connect battery ground cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH Fuse Block And Rear Body Harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8423 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8424 RH I/P Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch, LH > Page 8425 Door Switch: Locations Door Jamb Switch, Sliding Side Side Door Switches And Wiring In RH B-pillar Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Page 8426 C325, LH Door Jamb Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Fog/Driving Lamp Switch > Component Information > Locations Fog/Driving Lamp Switch: Locations Instrument Panel Fog Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Fog/Driving Lamp Switch > Component Information > Locations > Page 8430 Radio, Clock And Memory Feed Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations Headlamp Dimmer Switch: Locations Instrument Panel, LH Side On LH side of steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 8434 Headlamp Dimmer Switch: Service and Repair Fig. 19 Ignition Lock & Dimmer Switch Replacement. 1. Disconnect battery ground cable. 2. Remove lower steering column cover. 3. Remove washer head screw (54) and hexagon washer head tapping screw (69), Fig. 19. 4. Remove dimmer switch assembly, Fig. 19. 5. Remove flat head screw (67), then the ignition switch assembly with switch actuator rod, Fig. 19. 6. Remove switch actuating rod from ignition switch. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations Headlamp Switch: Locations Headlights Switch Wiring Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations > Page 8438 Instrument Panel, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions Headlamp Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except F-PUMP Fuel Pump FLASH Flasher Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8441 FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver SIR Supplemental Inflatable Restraint SKT Socket Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8442 SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature T/L Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8443 To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE(ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: Slide across the vehicle seat. - Sit down or stand up. - Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: - They are bumped or dropped. - They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8444 Symbols (Part 1 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8445 Symbols (Part 2 Of 3) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8446 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8447 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8448 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8449 Headlamp Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8450 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8451 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8452 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8453 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8454 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. - If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. - A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8455 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8456 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8457 Ohmmeter Meter Scales Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8458 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. - An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. - On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: - A range selector switch which permits the selection of different ranges of resistance. - A set adjust control which allows the meter to be set at zero for accurate measurements. - Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8459 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: - Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. - Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. - Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8460 be less than 10 percent of the total drop. When using a voltmeter: - Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. - Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. - The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: Check the accuracy and completeness of the complaint. - Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8461 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: - Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). - Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. - Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. - Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. - The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems - Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. - Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. - Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8462 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8463 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8464 Twisted/Shielded Wire Repair Twisted Wires/Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8465 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8466 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8467 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). - Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean - Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. - Roll crimp (13) and solder the terminal. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8468 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8469 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8470 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean - Terminal cavity of the connector body. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8471 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. - Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8472 C202, Headlight Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8473 Headlamp Switch: Electrical Diagrams Light Switch Details (Part 1 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 8474 Light Switch Details (Part 2 Of 2) Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Page 8475 Headlamp Switch: Description and Operation HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Headlamp circuit draws too much current. When the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off and resets automatically. When the Light Switch is in HEAD, the Headlamp Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beam Indicator also receives voltage along with the High Beams. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Diagrams > Page 8476 Headlamp Switch: Testing and Inspection HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Headlamp circuit draws too much current. When the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off and resets automatically. When the Light Switch is in HEAD, the Headlamp Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beam Indicator also receives voltage along with the High Beams. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Horn Switch > Component Information > Locations Horn Switch: Locations In steering wheel Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams Turn Signal Switch: Diagrams C207, Multi-Function Switch In-Line C207, Turn Signal Switch C207, Turn Signal Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 8483 C207, Turn Signal Switch C207, Turn Signal Switch In-Line C207, Turn Signal Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 8484 C207, Turn Signal Switch In-Line C207, Multi-Function Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 8485 Turn Signal Switch: Service and Repair Fig. 8 Lock Bolt Guard Removal. Fig. 17 Turn Signal Switch Replacement. 1. Place ignition switch in Lock position to prevent coil assembly from moving off center. 2. Disconnect battery ground cable. 3. Remove steering wheel. WARNING: Refer to Air Bags and Seat Belts/ Air Bags (Supplemental Restraint Systems)/ Service and Repair/ Air Bag System Disarming & Arming. 4. Remove coil assembly retaining ring from upper steering column. 5. Remove SIR coil assembly. Let coil assembly hang freely. 6. Remove wave washer. 7. On models with tilt steering column, remove lock bolt guard assembly, Fig. 8, as follows: a. Place ignition switch in Run position. b. Rotate steering shaft assembly until block tooth is at seven o'clock position and bolt guard screws are accessible through wide slots in shaft lock. c. Loosen screws on lock bolt guard until guard can be removed. d. Place ignition switch to Lock position. 8. Remove shaft lock retaining ring using tool No. J-23653-SIR, or equivalent, to push down shaft lock. Discard ring. 9. Remove shaft lock, Fig. 8. 10. Remove turn signal canceling cam assembly. 11. Remove upper bearing spring. 12. Remove upper bearing inner race and inner race seat. 13. Position turn signal to right turn position. 14. Remove multi-function lever and hazard knob assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Diagrams > Page 8486 15. Remove turn signal switch arm. 16. Remove turn signal switch as follows: a. Remove turn signal switch screws. b. Disconnect switch electrical connectors. c. Remove wiring protector, Fig. 17. d. Gently pull wiring harness through column to remove turn signal switch, Fig. 17. 17. Reverse procedure to install. Torque turn signal switch arm screw to 20.0 inch lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Tail Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement Tail Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Tail Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement > Page 8491 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Tail Lamp > Component Information > Technical Service Bulletins > Page 8492 Rear Lamp Wiring Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Tail Lamp > Component Information > Diagrams > LH C400, LH Tail, Stop And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Tail Lamp > Component Information > Diagrams > LH > Page 8495 C401, RH Tail, Stop And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Flasher > Component Information > Locations Turn Signal Flasher: Locations LH side of steering column Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement Turn Signal Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Lamp > Component Information > Technical Service Bulletins > Lighting - Exterior Lamp Condensation and Replacement > Page 8504 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Lamp > Component Information > Technical Service Bulletins > Page 8505 Turn Signal Lamp: Diagrams C136, RH Park And Turn Lamp C135, LH Park And Turn Lamp C400, LH Tail, Stop And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Lamp > Component Information > Technical Service Bulletins > Page 8506 C401, RH Tail, Stop And Turn Lamp Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Switch > Component Information > Diagrams Turn Signal Switch: Diagrams C207, Multi-Function Switch In-Line C207, Turn Signal Switch C207, Turn Signal Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Switch > Component Information > Diagrams > Page 8510 C207, Turn Signal Switch C207, Turn Signal Switch In-Line C207, Turn Signal Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Switch > Component Information > Diagrams > Page 8511 C207, Turn Signal Switch In-Line C207, Multi-Function Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Switch > Component Information > Diagrams > Page 8512 Turn Signal Switch: Service and Repair Fig. 8 Lock Bolt Guard Removal. Fig. 17 Turn Signal Switch Replacement. 1. Place ignition switch in Lock position to prevent coil assembly from moving off center. 2. Disconnect battery ground cable. 3. Remove steering wheel. WARNING: Refer to Air Bags and Seat Belts/ Air Bags (Supplemental Restraint Systems)/ Service and Repair/ Air Bag System Disarming & Arming. 4. Remove coil assembly retaining ring from upper steering column. 5. Remove SIR coil assembly. Let coil assembly hang freely. 6. Remove wave washer. 7. On models with tilt steering column, remove lock bolt guard assembly, Fig. 8, as follows: a. Place ignition switch in Run position. b. Rotate steering shaft assembly until block tooth is at seven o'clock position and bolt guard screws are accessible through wide slots in shaft lock. c. Loosen screws on lock bolt guard until guard can be removed. d. Place ignition switch to Lock position. 8. Remove shaft lock retaining ring using tool No. J-23653-SIR, or equivalent, to push down shaft lock. Discard ring. 9. Remove shaft lock, Fig. 8. 10. Remove turn signal canceling cam assembly. 11. Remove upper bearing spring. 12. Remove upper bearing inner race and inner race seat. 13. Position turn signal to right turn position. 14. Remove multi-function lever and hazard knob assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Turn Signals > Turn Signal Switch > Component Information > Diagrams > Page 8513 15. Remove turn signal switch arm. 16. Remove turn signal switch as follows: a. Remove turn signal switch screws. b. Disconnect switch electrical connectors. c. Remove wiring protector, Fig. 17. d. Gently pull wiring harness through column to remove turn signal switch, Fig. 17. 17. Reverse procedure to install. Torque turn signal switch arm screw to 20.0 inch lbs. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Lighting and Horns > Vanity Lamp > Component Information > Diagrams Vanity Lamp: Diagrams C378, Lighted Vanity Mirror C378, Lighted Vanity Mirror Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Heated Glass Element > Heated Glass Element Relay > Component Information > Locations Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Heated Glass Element > Heated Glass Element Relay > Component Information > Locations > Page 8522 Heated Glass Element Relay: Diagrams C235, Rear Window Defogger Relay C235, Defogger Timer Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Heated Glass Element > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch Heated Glass Element Switch: Locations Rear Defogger Switch Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Heated Glass Element > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch > Page 8527 Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Heated Glass Element > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch > Page 8528 Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Relays and Modules - Windows and Glass > Heated Glass Element Relay > Component Information > Locations Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Relays and Modules - Windows and Glass > Heated Glass Element Relay > Component Information > Locations > Page 8533 Heated Glass Element Relay: Diagrams C235, Rear Window Defogger Relay C235, Defogger Timer Relay Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch Heated Glass Element Switch: Locations Rear Defogger Switch Liftgate Wiring, RH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch > Page 8539 Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Rear Defogger Switch > Page 8540 Liftgate Wiring, LH Front Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations Door Wiring W/Power Door Locks, Power Windows And Power Mirrors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations > Page 8544 Power Window Switch: Diagrams C500, Front LH Power Window Switch C600, Front RH Power Window Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Power Window Motor > Component Information > Locations Door Wiring W/Power Door Locks, Power Windows And Power Mirrors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Power Window Motor > Component Information > Locations > Page 8549 Power Window Motor: Diagrams C601, Front RH Power Window Motor C505, Front LH Power Door Lock Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Power Window Motor > Component Information > Locations > Page 8550 Power Window Motor: Service and Repair Window Regulator Components Remove or Disconnect 1. Power window regulator. Refer to Window Regulator. See: Window Regulator/Service and Repair CAUTION: Step 2 must be performed when the regulator motor is removed from the regulator. The regulator lift arms are under tension from the counterbalance spring and can cause serious personal injury if the motor is removed without locking the sector gear in position. 2. Install a self-tapping, pan head sheet metal screw through the sector gear and backing plate at the hole provided to lock the sector gear into position. 3. Drill out the motor to regulator attaching rivets. ^ Motor from the regulator. Install or Connect 1. Motor to the regulator. A. Lubricate the motor drive gear and regulator sector teeth. B. Check the mesh of the motor to the regulator 2. Rivets to the motor and regulator. ^ Remove the sheet metal screw. 3. Regulator to the door. Refer to Power Window Regulator. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Power Window Switch > Component Information > Locations Door Wiring W/Power Door Locks, Power Windows And Power Mirrors Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Power Window Switch > Component Information > Locations > Page 8554 Power Window Switch: Diagrams C500, Front LH Power Window Switch C600, Front RH Power Window Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Glass > Back Window Glass > Component Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information Back Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Glass > Front Corner Window Glass > Component Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information Front Corner Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Glass > Front Door Window Glass > System Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information Front Door Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Glass > Front Door Window Glass > System Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information > Page 8568 Front Door Window Glass: Technical Service Bulletins Body - Side Window Chipping Information INFORMATION Bulletin No.: 06-08-64-001B Date: October 20, 2009 Subject: Information on Side Door Window Glass Chipping Caused by Hanging Vehicle Key Lock Box Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add vehicles and model years and to include all types of door window glass. Please discard Corporate Bulletin Number 06-08-64-001A (Section 08 - Body & Accessories). - In several warranty parts review cases, side door window glass was observed with a chip or chips on the top side of the window glass. Dealer contacts confirmed that they use a vehicle key lock box on the front side door window glass. - A random selection of side door glass returns will be conducted to confirm adherence. If a side door glass is discovered with a chip or chips in the location previously described, the side door glass will be returned to the dealership for debit. Example of Side Door Glass - DO NOT place a vehicle key lock box on a side door window glass. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Glass > Front Door Window Glass > System Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information > Page 8569 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Glass > Quarter Window Glass > Component Information > Technical Service Bulletins > Body - Vehicle Glass Distortion Information Quarter Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windows > Window Regulator > Component Information > Service and Repair Window Regulator: Service and Repair Window Regulator Components Remove or Disconnect 1. Negative battery cable. 2. Trim panel. Refer to Trim Panel. See: Body and Frame/Doors, Hood and Trunk/Doors 3. Armrest bracket and water deflector. Refer to Arm rest Bracket and Water Deflector. See: Body and Frame/Doors, Hood and Trunk/Doors Note: Roll the window up, and apply cloth backed body tape from the window over the top of the door to the other side of the window to hold the glass in position when the regulator is removed. 4. Wiring harness from the regulator motor (if equipped). 5. Regulator to door rivets. ^ Use a 6-mm (1/4-inch) drill bit to remove the head from the rivet. 6. Regulator from the door. A. Push the regulator into the door and slide it forward, then rearward to remove the regulator arms from the sash and the regulator rail. B. Fold the regulator arms together and remove the regulator from the access hole. Install or Connect Tool Required: M 39010 Heavy Duty Riveter 1. Regulator to the door. A. Place the regulator into the door through the access hole. B. Place the regulator arm rollers into the sash and the regulator rail. C. Push the regulator through the regulator door opening and align the holes in the regulator with the holes in the door. 2. Regulator to door rivets using M 39010. 3. Armrest bracket and water deflector. Refer to Armrest Bracket and Water Deflector. 4. Trim panel. Refer to Trim Panel. ^ Remove the tape from the door and window. 5. Negative battery cable. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > Customer Interest: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter Windshield: Customer Interest Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > Customer Interest: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter > Page 8585 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > Customer Interest: > 09-08-48-002A > Mar > 09 > Body - Marks/Stains on Windshield When Wet Windshield: Customer Interest Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance Windshield: All Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance > Page 8595 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 00-08-48-005D > Sep > 10 > Body - Vehicle Glass Distortion Information Windshield: All Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter Windshield: All Technical Service Bulletins Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 09-08-48-006 > Sep > 09 > Body - Stain/Film On Windshield Glass Perimeter > Page 8604 Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 09-08-48-002A > Mar > 09 > Body - Marks/Stains on Windshield When Wet Windshield: All Technical Service Bulletins Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit Windshield: All Technical Service Bulletins New Windshield/Glass Urethane Adhesive Caulking Kit File In Section: 10 - Body Bulletin No.: 83-15-16 Date: October, 1998 INFORMATION Subject: New Windshield and Stationary Glass Urethane Adhesive Caulking Kit Models: 1990-99 All Passenger Cars and Trucks As a result of a change from standard viscosity urethane to high-viscosity urethane, a new Urethane Adhesive Caulking Kit, P/N 12346392, is now available from GMSPO. This kit contains the "High Viscosity" Urethane Adhesive for thicker and more consistent bead size applications. When applied properly, this new high viscosity urethane in many instances will eliminate the need for depth setting blocks or the damming material to control squeeze out. The following is the contents of the new kit: Like the standard viscosity urethane contained in kit (P/N 12346284) that it replaces, it is a one-part, moisture cure product with curing times that vary as a result of changes in either temperature or humidity. THE REQUIRED TIME FOR THIS NEW ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer, IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. Alternate equivalent materials for this kit may be available from a local glass repair shop under the following product numbers: Other manufacturers of Urethane Adhesive that have documented their ability to meet or exceed General Motors specification # 3651M (Performance Requirements for Stationary Glass Bonding Adhesive System Service) are also considered to be equivalent to GM Kit (P/N 12346392). In previously published Corporate Bulletin Number 73-10-54, increasing customer demands for faster service have resulted in quicker two-part urethane adhesives to be made available. Essex Beta Seal U216* (two-part urethane adhesive) also meets the General Motors 3651M Specification and can be Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit > Page 8613 used when the customer demands quicker repair of the vehicle than the above described one-part product can provide. This two-part, chemical cure product requires ONE (1) TO ONE-AND-ONE-HALF (1-1/2) HOURS FOR CURING BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This two-part product also requires primers on the glass and pinchweld surfaces. The primers and applicator daubers are not included with this two-part product and therefore, must be purchased separately. In addition, this two-part product requires a special applicator (gun) for proper mixing and dispensing of the adhesive. Important: The U216 product is NOT available from GMSPO and must be obtained locally. * We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. When using either of the above described products, make sure to follow the manufacturer's directions for application and drying times. For information regarding the removal and installation of stationary glass, consult the appropriate Service Manual. Parts information P/N Description 12346392 Urethane Adhesive Caulking Kit Parts are expected to be available from GMSPO, 10/12/98. Important: The previously recommended adhesive kit (P/N 12346284) will no longer be available from GMSPO once inventory is exhausted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 72-05-04 > Aug > 97 > Warranty - Guidelines for Claiming Windshield Replace Windshield: All Technical Service Bulletins Warranty - Guidelines for Claiming Windshield Replace File In Section: Warranty Administration Bulletin No.: 72-05-04 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Claiming C0034 - Windshield Replacement Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with guidelines for using the above subject labor operations. In an effort to understand the windshield replacements, the following two phase approval process is being implemented. We feel this approach will allow GM to be responsive to repair decisions on vehicles over 10,000 miles (16,000KMS), while providing you, our dealers, the empowerment to address customer needs on those cases requiring repairs early in the vehicle's life, under 10,000 miles (16,000KMS). Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Windshield replacement on vehicles under 10,000 miles (16,0OOKMS) can only be made after Service Management inspection, review and approval. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. ^ Windshield replacement on vehicles over 10,000 miles (16,000KMS) can only be made after Service Management inspection, review and approval from the divisional service representative. Vehicles may be required to be held for wholesale inspection. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. The claim will require wholesale authorization for payment. Additional Requirements ^ Windshields replaced must be held for the normal parts retention period and the defect should be clearly identified on the glass by means of tape and/or a grease pencil. ^ Sublet windshield replacements, like other sublet repairs are to be claimed for actual dealership cost less any discounts and or allowances offered. Sublet repairs cannot exceed the normal allowance provided to the dealership had the repair been completed in-house. See your GM Policy and Procedure Manual for the complete guidelines. Windshields damaged by normal wear, road hazards, vandalism, or other physical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Windshield: > 73-10-54 > May > 97 > Windshield - Two-Part Urethane Adhesive For Installation Windshield: All Technical Service Bulletins Windshield - Two-Part Urethane Adhesive For Installation File In Section: 10 - Body Bulletin No.: 73-10-54 Date: May, 1997 INFORMATION Subject: Two-Part Urethane Adhesive For Windshield Installations Models: 1997 And Prior Passenger Cars and Trucks (Using Urethane Adhesive To Retain Windshields) General Motors passenger cars and trucks use urethane adhesive as a means to retain the windshield in the body opening. The urethane adhesive is used to bond the windshield in the opening, increasing vehicle structure. The current recommended urethane adhesive, GM P/N 12346284, is a one-part moisture cure product that requires a minimum curing period of 6 hours at room temperature before returning the vehicle to the customer. Increasing customer demands for faster service in recent years have resulted in quicker cure two-part urethane adhesives. Essex Beta Seal U216* (two-part urethane adhesive) meets the General Motors 3651M Specification (Performance Requirements for Stationary Glass Bonding Adhesive System Service) and can be used when the customer demands quicker repair of the vehicle than the current one-part materials can provide. Either of these products can be used when glass replacement is performed. The differences between these products are as follows: The CURRENT URETHANE ADHESIVE KIT, GM P/N 12346284, IS A ONE-PART ADHESIVE. It includes the necessary glass and pinchweld primers and is specified in Service Manuals for General Motors' vehicles. Since this is a "moisture cure" product, the curing time for this one-part material will vary with changes to either temperature or humidity. The REQUIRED TIME FOR THIS ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. ESSEX BETA SEAL U216 IS A TWO-PART ADHESIVE MATERIAL THAT PROVIDES FOR A ONE (1) TO ONE AND ONE HALF (11/2) HOUR CURE BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This product also requires primers on the glass and pinchweld surfaces. This product requires a special applicator for the mixing and dispensing of the adhesive. When using this (or any) product, make sure to follow the manufacturer's directions for application and drying times. Parts Information Parts are currently available from GMSPO. * We believe this source and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance Windshield: All Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 06-08-43-003C > Feb > 11 > Glass/Body - Windshield Wiper Performance > Page 8627 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 00-08-48-005D > Sep > 10 > Body - Vehicle Glass Distortion Information Windshield: All Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit Windshield: All Technical Service Bulletins New Windshield/Glass Urethane Adhesive Caulking Kit File In Section: 10 - Body Bulletin No.: 83-15-16 Date: October, 1998 INFORMATION Subject: New Windshield and Stationary Glass Urethane Adhesive Caulking Kit Models: 1990-99 All Passenger Cars and Trucks As a result of a change from standard viscosity urethane to high-viscosity urethane, a new Urethane Adhesive Caulking Kit, P/N 12346392, is now available from GMSPO. This kit contains the "High Viscosity" Urethane Adhesive for thicker and more consistent bead size applications. When applied properly, this new high viscosity urethane in many instances will eliminate the need for depth setting blocks or the damming material to control squeeze out. The following is the contents of the new kit: Like the standard viscosity urethane contained in kit (P/N 12346284) that it replaces, it is a one-part, moisture cure product with curing times that vary as a result of changes in either temperature or humidity. THE REQUIRED TIME FOR THIS NEW ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer, IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. Alternate equivalent materials for this kit may be available from a local glass repair shop under the following product numbers: Other manufacturers of Urethane Adhesive that have documented their ability to meet or exceed General Motors specification # 3651M (Performance Requirements for Stationary Glass Bonding Adhesive System Service) are also considered to be equivalent to GM Kit (P/N 12346392). In previously published Corporate Bulletin Number 73-10-54, increasing customer demands for faster service have resulted in quicker two-part urethane adhesives to be made available. Essex Beta Seal U216* (two-part urethane adhesive) also meets the General Motors 3651M Specification and can be Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 83-15-16 > Oct > 98 > New Windshield/Glass Urethane Adhesive Caulking Kit > Page 8636 used when the customer demands quicker repair of the vehicle than the above described one-part product can provide. This two-part, chemical cure product requires ONE (1) TO ONE-AND-ONE-HALF (1-1/2) HOURS FOR CURING BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This two-part product also requires primers on the glass and pinchweld surfaces. The primers and applicator daubers are not included with this two-part product and therefore, must be purchased separately. In addition, this two-part product requires a special applicator (gun) for proper mixing and dispensing of the adhesive. Important: The U216 product is NOT available from GMSPO and must be obtained locally. * We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. When using either of the above described products, make sure to follow the manufacturer's directions for application and drying times. For information regarding the removal and installation of stationary glass, consult the appropriate Service Manual. Parts information P/N Description 12346392 Urethane Adhesive Caulking Kit Parts are expected to be available from GMSPO, 10/12/98. Important: The previously recommended adhesive kit (P/N 12346284) will no longer be available from GMSPO once inventory is exhausted. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 72-05-04 > Aug > 97 > Warranty - Guidelines for Claiming Windshield Replace Windshield: All Technical Service Bulletins Warranty - Guidelines for Claiming Windshield Replace File In Section: Warranty Administration Bulletin No.: 72-05-04 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Claiming C0034 - Windshield Replacement Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with guidelines for using the above subject labor operations. In an effort to understand the windshield replacements, the following two phase approval process is being implemented. We feel this approach will allow GM to be responsive to repair decisions on vehicles over 10,000 miles (16,000KMS), while providing you, our dealers, the empowerment to address customer needs on those cases requiring repairs early in the vehicle's life, under 10,000 miles (16,000KMS). Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Windshield replacement on vehicles under 10,000 miles (16,0OOKMS) can only be made after Service Management inspection, review and approval. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. ^ Windshield replacement on vehicles over 10,000 miles (16,000KMS) can only be made after Service Management inspection, review and approval from the divisional service representative. Vehicles may be required to be held for wholesale inspection. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. The claim will require wholesale authorization for payment. Additional Requirements ^ Windshields replaced must be held for the normal parts retention period and the defect should be clearly identified on the glass by means of tape and/or a grease pencil. ^ Sublet windshield replacements, like other sublet repairs are to be claimed for actual dealership cost less any discounts and or allowances offered. Sublet repairs cannot exceed the normal allowance provided to the dealership had the repair been completed in-house. See your GM Policy and Procedure Manual for the complete guidelines. Windshields damaged by normal wear, road hazards, vandalism, or other physical damage are not eligible for warranty coverage. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Windows and Glass > Windshield > Component Information > Technical Service Bulletins > All Other Service Bulletins for Windshield: > 73-10-54 > May > 97 > Windshield - Two-Part Urethane Adhesive For Installation Windshield: All Technical Service Bulletins Windshield - Two-Part Urethane Adhesive For Installation File In Section: 10 - Body Bulletin No.: 73-10-54 Date: May, 1997 INFORMATION Subject: Two-Part Urethane Adhesive For Windshield Installations Models: 1997 And Prior Passenger Cars and Trucks (Using Urethane Adhesive To Retain Windshields) General Motors passenger cars and trucks use urethane adhesive as a means to retain the windshield in the body opening. The urethane adhesive is used to bond the windshield in the opening, increasing vehicle structure. The current recommended urethane adhesive, GM P/N 12346284, is a one-part moisture cure product that requires a minimum curing period of 6 hours at room temperature before returning the vehicle to the customer. Increasing customer demands for faster service in recent years have resulted in quicker cure two-part urethane adhesives. Essex Beta Seal U216* (two-part urethane adhesive) meets the General Motors 3651M Specification (Performance Requirements for Stationary Glass Bonding Adhesive System Service) and can be used when the customer demands quicker repair of the vehicle than the current one-part materials can provide. Either of these products can be used when glass replacement is performed. The differences between these products are as follows: The CURRENT URETHANE ADHESIVE KIT, GM P/N 12346284, IS A ONE-PART ADHESIVE. It includes the necessary glass and pinchweld primers and is specified in Service Manuals for General Motors' vehicles. Since this is a "moisture cure" product, the curing time for this one-part material will vary with changes to either temperature or humidity. The REQUIRED TIME FOR THIS ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. ESSEX BETA SEAL U216 IS A TWO-PART ADHESIVE MATERIAL THAT PROVIDES FOR A ONE (1) TO ONE AND ONE HALF (11/2) HOUR CURE BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This product also requires primers on the glass and pinchweld surfaces. This product requires a special applicator for the mixing and dispensing of the adhesive. When using this (or any) product, make sure to follow the manufacturer's directions for application and drying times. Parts Information Parts are currently available from GMSPO. * We believe this source and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Locations Multi-Function Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch C415, Wiper Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 8652 Wiper Switch: Diagrams Multi-Function Switch In-Line C207, Multi-Function Switch In-Line C207, Multi-Function Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 8653 C415, Motor To Wiper Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8654 Wiper Switch: Service and Repair Remove or Disconnect NOTICE: Place ignition to "LOCK" position to prevent uncentering coil assembly (3). 1. Disable the SIR system. 2. Negative (-) battery cable. 3. Coil assembly retaining ring (2). 4. Inflatable restraint coil assembly (3). a). Let switch hang freely if removal is not needed. b). To remove coil assembly (3), do steps 5 through 17. 5. Wave washer (4). 6. Shaft lock spacer (7). 7. Shaft lock retaining ring (8) using 3 23653-SIR to push down shaft lock (9). Dispose of ring (8). 8. Shaft lock (9) from steering shaft assembly (46). 9. Turn signal cancel cam assembly (10). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8655 10. Upper bearing spring (11). 11. Thrust washer (17). 12. Turn signal to "RIGHT TURN" position (up). 13. Multi-function lever and hazard knob assembly. 14. Washer head screw (13) and switch actuator arm (14). 15. Three cross recess screws (12). 16. Turn signal switch assembly (15). Let switch hang freely, if removal is not needed. To remove, turn signal switch (15). a). Turn signal switch connector from vehicle wire harness and connector body bracket assembly (56). b). Hexagon nut (57). c). Connector body bracket (56). d). Wiring protector (43). e). Turn signal switch (15) connector through column. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8656 NOTICE: Coil assembly (3) will become uncentered if: 1). Steering column is separated from steering gear and is allowed to rotate, or 2). Centering spring is pushed down, letting hub rotate while coil (3) is removed from steering column. 17. Inflatable restraint coil assembly (3) with wire harness from column assembly. a). Wiring protector (43). b). Ensure that connector shroud (5) has been removed. Attach a length of mechanics wire to terminal connector to aid in reassembly. c). Gently pull wire through column. NOTICE: When removing buzzer switch assembly (18) buzzer switch retaining clip (42) may become disconnected. Ensure that retaining clip (42) does not drop into column assembly. Failure to do so may result in component damage or malfunctioning of steering column. 18. Buzzer switch assembly (18) with buzzer switch retaining clip (42). Clip (42) from buzzer switch (18). 19. Lock retaining screw (19). 20. Steering column lock cylinder set (22). Install or Connect NOTICE: Ensure all fasteners are securely seated before applying needed torque. Failure to do so may result in component damage or malfunctioning of steering column. 1. Steering column lock cylinder set (22). 2. Lock retaining screw (19). Tighten screw (19) to 4.5 N-m (40 lb.in.) 3. Buzzer switch retaining clip (42) to buzzer switch (18). Buzzer switch (18) with retaining clip (42) to steering column housing assembly (20). Ensure that clip (42) does not drop into column assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8657 4. Coil assembly (3) wire harness through column. Let coil hang freely. 5. Turn signal switch assembly (15) wire harness through steering column. a). Wire protector (43). b). Connector body bracket (56) with hexagon nut (57). Tighten nut (57) to 4.0 N-m (35 lb.in.). c). Turn signal switch (15) connector to vehicle wire harness and connector body bracket (56). 6. Turn signal switch assembly (15) with screws (12). Tighten screws (12) to 3.4 N-m (30 lb.in.). 7. Switch actuator arm (14) and screw (13). Tighten screw (13) to 2.3 N-m (20 lb.in.). 8. Hazard knob assembly and multi-function lever. 9. Thrust washer (17). 10. Upper bearing spring (11). 11. Turn signal cancel cam assembly (10). Lubricate with grease, synthetic (service kit). 12. Shaft lock (9). 13. New shaft lock retaining ring (8) using J 23653-SIR to push down shaft lock (9). Ring (8) must be firmly seated in groove on shaft. 14. Shaft lock spacer (7). NOTICE: Set steering shaft so that block tooth on upper steering shaft (46) is at the 12 o'clock position, wheels on vehicle should be straight ahead, then set ignition switch to "LOCK" position, to ensure no damage to coil assembly (3). 15. Wave washer (4). NOTICE: Coil assembly (3) will become uncentered if: 1) Steering column is separated from steering gear and is allowed to rotate, or 2) Centering spring is pushed down, letting hub rotate while coil is removed from column. NOTICE: If a new coil assembly (3) is being installed, assemble pre-centered coil assembly (3) to steering column. Remove centering tab and Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8658 dispose. NOTICE: SIR coil assembly wire must be kept tight with no slack while installing SIR coil assembly. Failure to do so may cause wire to be kinked near shaft lock area and cut when steering wheel is turned. 16. Ensure coil assembly (3) hub is centered. 17. Coil assembly (3). a). Pull wires tight while positioning SIR coil to steering shaft. b). Align opening in coil with horn tower and "locating bump" between two tabs on housing cover. c). Seat coil assembly into steering column. d). Connector shroud (5). 18. Coil assembly retaining ring (2). Ring (2) must be firmly seated in groove on shaft. NOTICE: Gently pull lower coil assembly and turn signal harness to remove any wire kinks that may be inside steering column assembly. Failure to do so may cause damage to wire harness. 19. Wiring protector (43). 20. Negative (-) battery cable. 21. If all service operations are completed, enable the SIR system. Inspect a). Function check turn signal switch (15). b). Position switch lever to right turn position. Turn steering wheel to left. Switch should cancel to center position. c). Repeat above procedure for left turn position. d). If turn signal switch does not return to center position check switch (15) forbroken or missing cancel spring, or a worn or damaged cancel cam (10). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Windshield Washer Pump > Component Information > Locations Engine Compartment Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Windshield Washer Pump > Component Information > Locations > Page 8662 Windshield Washer Pump: Diagrams C138, Windshield Washer Pump C143, Washer Pump Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Windshield Washer Reservoir > Component Information > Locations Windshield Washer Reservoir: Locations Engine Compartment Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Windshield Washer Reservoir > Component Information > Locations > Page 8666 Engine Compartment Wiring, RH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Blade > Component Information > Technical Service Bulletins > Glass/Body - Windshield Wiper Performance Wiper Blade: Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Blade > Component Information > Technical Service Bulletins > Glass/Body - Windshield Wiper Performance > Page 8671 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Technical Service Bulletins > Customer Interest for Wiper Motor: > 468201 > May > 94 > Windshield Wiper - Unwanted Phantom Wipe/Single Cycle Wiper Motor: Customer Interest Windshield Wiper - Unwanted Phantom Wipe/Single Cycle Group Ref.: Chassis/Body Electrical Bulletin No.: 468201 Date: May, 1994 SUBJECT: PHANTOM WIPE/SINGLE UNWANTED CYCLE OF WINDSHIELD WIPER (REPLACE PULSE WIPER CIRCUIT BOARD) MODELS: 1993-94 CHEVROLET AND GMC TRUCK C/K, G, P, M/L MODELS 1993-94 CHEVROLET AND GMC TRUCK TOPKICK/KODIAK MODELS 1994 CHEVROLET AND GMC TRUCK S/T PICKUPS CONDITION: With the wiper switch in the off position one to ten minutes after turning the ignition switch on, the wipers will cycle once then return to the rest position. CAUSE: A leaking diode in the windshield wiper control circuit board. CORRECTION: Replace the circuit board with an updated version that eliminates the leaking diode. Part numbers of affected wiper assemblies (production P/N found on black label of wiper motor). Julian date codes of the above affected part numbers range from 17293X to 23093X. The X represents the shift the component was produced on (1, 2, or 3). Wiper motor assemblies with Julian date codes higher than 23193X have already been updated. SERVICE PARTS INFORMATION: P/N Description QTY 22101636 Circuit Board All 1 Above Wiper Motors Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Operation Description Labor Time N3570 Module, Pulse Use Published Wiper Control - Labor Operation Replace Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wiper Motor: > 468201 > May > 94 > Windshield Wiper - Unwanted Phantom Wipe/Single Cycle Wiper Motor: All Technical Service Bulletins Windshield Wiper - Unwanted Phantom Wipe/Single Cycle Group Ref.: Chassis/Body Electrical Bulletin No.: 468201 Date: May, 1994 SUBJECT: PHANTOM WIPE/SINGLE UNWANTED CYCLE OF WINDSHIELD WIPER (REPLACE PULSE WIPER CIRCUIT BOARD) MODELS: 1993-94 CHEVROLET AND GMC TRUCK C/K, G, P, M/L MODELS 1993-94 CHEVROLET AND GMC TRUCK TOPKICK/KODIAK MODELS 1994 CHEVROLET AND GMC TRUCK S/T PICKUPS CONDITION: With the wiper switch in the off position one to ten minutes after turning the ignition switch on, the wipers will cycle once then return to the rest position. CAUSE: A leaking diode in the windshield wiper control circuit board. CORRECTION: Replace the circuit board with an updated version that eliminates the leaking diode. Part numbers of affected wiper assemblies (production P/N found on black label of wiper motor). Julian date codes of the above affected part numbers range from 17293X to 23093X. The X represents the shift the component was produced on (1, 2, or 3). Wiper motor assemblies with Julian date codes higher than 23193X have already been updated. SERVICE PARTS INFORMATION: P/N Description QTY 22101636 Circuit Board All 1 Above Wiper Motors Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Operation Description Labor Time N3570 Module, Pulse Use Published Wiper Control - Labor Operation Replace Time Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Locations > Wiper Motor, Front Wiper Motor: Locations Wiper Motor, Front Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Locations > Wiper Motor, Front > Page 8687 Engine Compartment Wiring, LH Side Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Locations > Wiper Motor, Front > Page 8688 Wiper Motor: Locations Wiper Motor, Rear Liftgate Wiring Harness To Liftgate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Locations > Wiper Motor, Front > Page 8689 Liftgate Wiring Harness To Liftgate Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Locations > Page 8690 Wiper Motor: Diagrams C137, Wiper Motor C911, Rear Wiper Motor Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Motor > Component Information > Locations > Page 8691 Wiper Motor: Service and Repair Fig. 26 Wiper Motor Replacement 1. Disconnect battery ground cable. 2. Remove wiper arm assemblies, Fig. 26. 3. Remove cowl vent grille. 4. Disconnect wiper motor electrical connector. 5. Remove transmission drive link from crank arm by prying it toward the rear of the vehicle. 6. Remove wiper motor bolts, then the wiper motor from vehicle, Fig. 26. 7. Reverse procedure to install. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Locations Multi-Function Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch C415, Wiper Switch Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 8697 Wiper Switch: Diagrams Multi-Function Switch In-Line C207, Multi-Function Switch In-Line C207, Multi-Function Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 8698 C415, Motor To Wiper Switch In-Line Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8699 Wiper Switch: Service and Repair Remove or Disconnect NOTICE: Place ignition to "LOCK" position to prevent uncentering coil assembly (3). 1. Disable the SIR system. 2. Negative (-) battery cable. 3. Coil assembly retaining ring (2). 4. Inflatable restraint coil assembly (3). a). Let switch hang freely if removal is not needed. b). To remove coil assembly (3), do steps 5 through 17. 5. Wave washer (4). 6. Shaft lock spacer (7). 7. Shaft lock retaining ring (8) using 3 23653-SIR to push down shaft lock (9). Dispose of ring (8). 8. Shaft lock (9) from steering shaft assembly (46). 9. Turn signal cancel cam assembly (10). Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8700 10. Upper bearing spring (11). 11. Thrust washer (17). 12. Turn signal to "RIGHT TURN" position (up). 13. Multi-function lever and hazard knob assembly. 14. Washer head screw (13) and switch actuator arm (14). 15. Three cross recess screws (12). 16. Turn signal switch assembly (15). Let switch hang freely, if removal is not needed. To remove, turn signal switch (15). a). Turn signal switch connector from vehicle wire harness and connector body bracket assembly (56). b). Hexagon nut (57). c). Connector body bracket (56). d). Wiring protector (43). e). Turn signal switch (15) connector through column. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8701 NOTICE: Coil assembly (3) will become uncentered if: 1). Steering column is separated from steering gear and is allowed to rotate, or 2). Centering spring is pushed down, letting hub rotate while coil (3) is removed from steering column. 17. Inflatable restraint coil assembly (3) with wire harness from column assembly. a). Wiring protector (43). b). Ensure that connector shroud (5) has been removed. Attach a length of mechanics wire to terminal connector to aid in reassembly. c). Gently pull wire through column. NOTICE: When removing buzzer switch assembly (18) buzzer switch retaining clip (42) may become disconnected. Ensure that retaining clip (42) does not drop into column assembly. Failure to do so may result in component damage or malfunctioning of steering column. 18. Buzzer switch assembly (18) with buzzer switch retaining clip (42). Clip (42) from buzzer switch (18). 19. Lock retaining screw (19). 20. Steering column lock cylinder set (22). Install or Connect NOTICE: Ensure all fasteners are securely seated before applying needed torque. Failure to do so may result in component damage or malfunctioning of steering column. 1. Steering column lock cylinder set (22). 2. Lock retaining screw (19). Tighten screw (19) to 4.5 N-m (40 lb.in.) 3. Buzzer switch retaining clip (42) to buzzer switch (18). Buzzer switch (18) with retaining clip (42) to steering column housing assembly (20). Ensure that clip (42) does not drop into column assembly. Chevrolet Astro Van M Workshop Manual (V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 8702 4. Coil assembly (3) wire harness through column. Let coil hang freely. 5. Turn signal switch assembly (15) wire harness through steering column. a). Wire protector (43). b). Connector body bracket (56) with hexagon nut (57). Tighten nut (57) to 4.0 N-m (35 lb.in.). c). Turn signal switch (15) connector to vehicle wire harness and connector body bracket (56). 6. Turn signal switch assembly (15) with screws (12). Tighten screws (12) to 3.4 N-m (30 lb.in.). 7. Switch actuator arm (14) and screw (13). Tighten screw (13) to 2.3 N-m (20 lb.in.). 8. Hazard knob assembly and multi-function lever. 9. Thrust washer (17). 10. Upper bearing spring (11). 11. Turn signal cancel cam assembly (10). Lubricate with grease, synthetic (service kit). 12. Shaft lock (9). 13. New shaft lock retaining ring (8) using J 23653-SIR to push down shaft lock (9). Ring (8) must be firmly seated in groove on shaft. 14. Shaft lock spacer (7). NOTICE: Set steering shaft so that block tooth on upper steering shaft (46) is at the 12 o'clock position, wheels on vehicle should be straight ahead, then set ignition switch to "LOCK" position, to ensure no damage to coil assembly (3). 15. Wave washer (4). NOTICE: Coil assembly (3) will become uncentered if: 1) Steering column is separated from steering gear and is allowed to rotate, or 2) Centering spring is pushed down, letting hub rotate while coil is removed from column. NOTICE: If a new coil assembly (3) is being installed, assemble pre-centered coil assembly (3) to steering column. Remove centering tab and